Essential Clinical Procedures 2nd Edition

1600 John F. Kennedy Blvd. Ste 1800 Philadelphia, PA 19103-2899

ESSENTIAL CLINICAL PROCEDURES

ISBN-13: ISBN-10:

978-1-4160-3001-0 1-4160-3001-8

Copyright © 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. Permissions may be sought directly from Elsevier’s Health Sciences Rights Department in Philadelphia, PA, USA: phone: (+1) 215 239 3804, fax: (+1) 215 239 3805, e-mail: [email protected]. You may also complete your request on-line via the Elsevier homepage (http://www.elsevier.com), by selecting ‘Customer Support’ and then ‘Obtaining Permissions’.

Notice Knowledge and best practice in General and Internal Medicine are constantly changing. As new research and experience broaden our knowledge, changes in practice, treatment, and drug therapy may become necessary or appropriate. Readers are advised to check the most current information provided (i) on procedures featured or (ii) by the manufacturer of each product to be administered, to verify the recommended dose or formula, the method and duration of administration, and contraindications. It is the responsibility of the practitioner, relying on their own experience and knowledge of the patient, to make diagnoses, to determine dosages and the best treatment for each individual patient, and to take all appropriate safety precautions. To the fullest extent of the law, neither the Publisher nor the Editors assume any liability for any injury and/or damage to persons or property arising out of or related to any use of the material contained in this book. The Publisher

Previous edition copyrighted 2002 Library of Congress Cataloging-in-Publication Data Essential clinical procedures / [edited by] Richard W. Dehn, David P. Asprey– –2nd ed. p. ; cm. Rev. ed. of: Clinical procedures for physician assistants. c2002. Includes bibliographical references and index. ISBN-13: 978-1-4160-3001-0 ISBN-10: 1-4160-3001-8 1. Physicians’ assistants. I. Dehn, Richard W. II. Asprey, David P. III. Clinical procedures for physician assistants. [DNLM: 1. Diagnostic Techniques and Procedures. 2. Physician Assistants. WB 141 E776 2006] R697.P45C56 2006 610.73’72069– –dc22 2006028605 Acquisitions Editor: Rolla Couchman Editorial Assistant: Dylan Parker Publishing Services Manager: Frank Polizzano Project Manager: Michael H. Goldberg Design Direction: Steven Stave Printed in China Last digit is the print number:

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This book is dedicated to all physician assistants who are learning the science and art of practicing medicine as a physician assistant. While working on this edition, my father, Frank W. Dehn, suddenly contracted leukemia and died on October 3, 2005, at the age of 85, and I would also like to dedicate this book in loving memory of him. Additionally, I would like to thank my wife Elizabeth, and my children Jonathan, Michael, Clare, and Kelley, without whose support I could not have finished this project. —RWD To my wife Jill and my children Laura, Nolan, and Caleb thank you for supporting me in each of my endeavors and for the sacrifices that each of you has made to help me complete this text. I dedicate this edition of the text to my brother Randy Asprey, who died on July 17, 2006, at age 38 after a long and valiant battle with colon cancer. The courage and love you demonstrated as a husband, father, son, brother, and friend in the midst of this trial was truly remarkable and you will be greatly missed. —DPA

Contributors David P. Asprey, PhD, PA-C Associate Professor and Program Director, Physician Assistant Program, University of Iowa Carver College of Medicine, Iowa City, Iowa Documentation

Patrick C. Auth, PhD, PA-C Program Director and Assistant Professor, Drexel University Hahnemann Physician Assistant Program, Philadelphia, Pennsylvania Incision and Drainage of an Abscess

Salah Ayachi, PhD, PA-C Associate Professor and Associate Director, Physician Assistant Studies, School of Allied Health Sciences, University of Texas Medical Branch, Galveston, Texas Recording an Electrocardiogram

George S. Bottomley, DVM, PA-C Associate Professor and Program Director, Physician Assistant Program, Pennsylvania College of Optometry, Elkins Park, Pennsylvania Incision and Drainage of an Abscess

Anthony Brenneman, MPAS, PA-C Assistant Clinical Professor and Director of Clinical Education, Physician Assistant Program, University of Iowa Carver College of Medicine, Iowa City, Iowa Procedural Sedation

Darwin Brown, MPH, PA-C Assistant Professor, Physician Assistant Program, University of Nebraska Medical Center, Omaha, Nebraska Obtaining Blood Cultures; Draining Subungual Hematomas

Lynn E. Caton, MPAS, PA-C Assistant Professor of Family Medicine/PA Education and Associate Director for Clinical Education, Oregon Health & Science University School of Medicine, Physician Assistant Program, Portland, Oregon Outpatient Coding

L. Gail Curtis, MPAS, PA-C Assistant Professor, Wake Forest University School of Medicine, Department of Family and Community Medicine, Winston-Salem, North Carolina The Pelvic Examination and Obtaining a Routine Papanicolaou Smear

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Contributors

Randy Danielsen, PhD, PA-C Professor and Dean, Arizona School of Health Sciences, A.T. Still University, Mesa, Arizona Blood Pressure Measurement

Ellen Davis-Hall, PhD, PA-C Academic Coordinator and Associate Professor, Department of Pediatrics, University of Colorado Health Sciences Center, Child Health Associate Physician Assistant Program, Aurora, Colorado Inserting Intravenous Catheters

Richard W. Dehn, MPA, PA-C Clinical Professor and Assistant Director, Physician Assistant Program, University of Iowa Carver College of Medicine, Iowa City, Iowa Examination of the Male Genitalia

Michelle DiBaise, MPAS, PA-C Adjunct Assistant Professor, Arizona School of the Health Sciences, A.T. Still University, Mesa, Arizona Local Anesthesia; Dermatologic Procedures

Roger A. Elliott, MPH, PA-C Associate Professor and Associate Director, University of Oklahoma Physician Associate Program, University of Oklahoma College of Medicine, Oklahoma City, Oklahoma Office Pulmonary Function Testing

Donald R. Frosch, MS, PA-C Assistant Professor and Research and Assessment Coordinator, Physician Assistant Program, Butler University/Clarian Health, Indianapolis, Indiana Casting and Splinting

F.J. Gianola, PA Lecturer, MEDEX Northwest Physician Assistant Program, Division of Physician Assistant Studies, School of Medicine and Center for Health Sciences Interprofessional Education and Research, University of Washington, Seattle, Washington Giving Sad and Bad News

Jonathon W. Gietzen, MS, PA-C Assistant Professor, Pacific University School of Physician Assistant Studies, Forest Grove, Oregon Trauma-Oriented Ocular Examination, Corneal Abrasion, and Ocular Foreign Body Removal

Contributors

Kenneth R. Harbert, PhD, CHES, PA-C Dean, South College, Knoxville, Tennesse Venipuncture

Theresa E. Hegmann, MPAS, PA-C Assistant Clinical Professor and Director of Curriculum and Evaluation, Physician Assistant Program, University of Iowa Carver College of Medicine, Iowa City, Iowa Cryosurgery

Paul C. Hendrix, MHS, PA-C Associate Clinical Professor of Surgery and Director of the Physician Assistant Surgical Residency Program, Duke University School of Medicine, Durham, North Carolina Sterile Technique

Paul F. Jacques, EdM, PA-C Assistant Professor and Associate Chair for Clinical Research, Department of Clinical Services, Medical University of South Carolina, Charleston, South Carolina Wound Dressing Techniques

P. Eugene Jones, PhD, PA-C Professor and Chair, Department of Physician Assistant Studies; Editor-inChief, Journal of Physician Assistant Education, University of Texas Southwestern Medical Center, Dallas, Texas Cryosurgery

Nikki L. Katalanos, PhD, CDE, PA-C Professor and Chair, Department of Physician Assistant Studies; Editor-inChief, Journal of Physician Assistant Education, University of Texas Southwestern Medical Center, Dallas, Texas Foot Examination of the Patient with Diabetes

Patricia Kelly, EdD, MHS, PA-C Associate Professor and Chair, Department of Health Science, and Director, Doctor of Health Science Program, Nova Southeastern University, Fort Lauderdale, Florida Clinical Breast Examination

Charles S. King, PA-C Clinical Coordinator, Physician Assistant Program, University of Utah School of Medicine, Salt Lake City, Utah Exercise Stress Testing for the Primary Care Provider

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Patrick Knott, PhD, PA-C Associate Professor and Chair, Physician Assistant Department, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois Casting and Splinting

Daniel L. McNeill, PhD, PA-C Professor and Director, Physician Associate Program, University of Oklahoma College of Medicine, Oklahoma City, Oklahoma Office Pulmonary Function Testing

Dawn Morton-Rias, EdD, PA-C Dean and Assistant Professor, College of Health Related Professions, State University of New York, Downstate Medical Center, Brooklyn, New York Flexible Sigmoidoscopy

Richard D. Muma, PhD, MPH, PA-C Chair and Associate Professor, College of Health Professions, Department of Physician Assistant, Wichita State University, Wichita, Kansas Patient Education Concepts

Karen A. Newell, MMSc, PA-C Academic Coordinator, Emory University School of Medicine, Physician Assistant Program, Atlanta, Georgia Wound Closure

Sue M. Nyberg, MHS, PA-C Assistant Professor, Department of Physician Assistant, College of Health Professions, Wichita State University, Wichita, Kansas Treating Ingrown Toenails; Anoscopy

Claire Babcock O’Connell, MPH, PA-C Associate Professor, Physician Assistant Program, University of Medicine and Dentistry of New Jersey Robert Wood Johnson Medical School, Piscataway, New Jersey Arterial Puncture

Daniel L. O’Donoghue, PhD, PA-C Associate Professor, Physician Associate Program, University of Oklahoma College of Medicine, Oklahoma City, Oklahoma Office Pulmonary Function Testing

Martha Petersen, MPH, PA-C Assistant Professor, Department of Physician Assistant, Rangos School of Health Sciences, Duquesne University, Pittsburgh, Pennsylvania Endometrial Biopsy

Contributors

Richard R. Rahr, MBA, EdD, PA-C Professor and Chair, Physician Assistant Studies, School of Allied Health Sciences, University of Texas Medical Branch, Galveston, Texas Recording an Electrocardiogram

Tammy Dowdell Ream, MPAS, PA-C Assistant Professor and Coordinator of Clinical Education, Texas Tech University Health Sciences Center, School of Allied Health Sciences, Physician Assistant Program, Midland, Texas Removal of Cerumen and Foreign Bodies from the Ear

Conrad J. Rios, NP, PA, MSN Clinical Coordinator and Faculty, University of California at Davis Family Nurse Practitioner/Physician Assistant Program, Sacramento, California Injections

Ted J. Ruback, MS, PA-C Associate Professor and Head, Division of Physician Assistant Education, and Director, Physician Assistant Program, Oregon Health & Science University School of Medicine, Portland, Oregon Informed Consent

Virginia Fallaw Schneider, PA-C Assistant Professor, Departments of Pediatrics and Family and Community Medicine, Baylor College of Medicine, Houston, Texas Lumbar Puncture

Gary R. Sharp, MPH, PA-C Associate Professor and Clinical Coordinator, Physician Associate Program, University of Oklahoma College of Medicine, Oklahoma City, Oklahoma Office Pulmonary Function Testing

Shepard B. Stone, MPS, PA Associate Clinical Professor of Anesthesiology, Yale University School of Medicine; Physician Associate Anesthesiologist, Yale–New Haven Hospital, New Haven, Connecticut; State Aviation Medicine Officer, Connecticut Army National Guard, Niantic, Connecticut Endotracheal Intubation

Kirsten Thomsen, PA-C Adjunct Assistant Professor, The George Washington University School of Medicine and Health Sciences, Physician Assistant Program, Washington, DC Standard Precautions

Dan Vetrosky, MEd, PA-C Assistant Professor and Academic Coordinator, Department of Physician Assistant Studies, University of South Alabama, Mobile, Alabama Nasogastric Tube Placement; Urinary Bladder Catheterization

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M.F. Winegardner, MPAS, PA-C Physician Assistant, Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota Joint and Bursal Aspiration

Preface In writing this book regarding common clinical procedures for medical practitioners, we hope to fill a unique need for an area of clinical practice that is vital to clinical education and the practice of medicine. Members of both the physician assistant (PA) and nurse practitioner (NP) professions have prided themselves on their ability to function as a part of the health care team that can fill almost any role that is needed, including the performance of clinical procedures. As the professions have evolved, using PAs and NPs in roles that provide greater autonomy and responsibility has served to increase the importance of a curriculum that incorporates common clinical procedures as part of the preparation of competent clinicians. In attempting to accomplish this goal we have turned to our colleagues who are involved in clinical education, as either core faculty or clinical preceptors, who are very aware of the clinical procedure skills that clinical practice requires. Although we recognize that this textbook does not cover every procedure that a PA or NP may be asked to perform in practice, it does address a majority of the commonly occurring clinical procedures, and most were selected based on data that support the frequency with which PAs perform these procedures in primary care settings. We are forever indebted to the hundreds of bright, caring, compassionate, and pioneering men and women who founded our profession. They ventured into this career with little assurance that they would have a job or a career, much less a dependable income. They have made it into one of the most rewarding professions in existence today. Their vision, dedication, endurance, ingenuity, and concern for the best interest of their patients continue to be a motivating force for us as PA educators. We would also like to recognize the hundreds of colleagues with whom we share the role and title of PA educator. These individuals often give up freely the opportunity for the greater income and greater control of their schedule that can often be found in private practice to help prepare the next generation of PAs. We find the dedication and commitment of PA educators to their profession truly inspiring. We owe a great debt of gratitude to students. Without their eager thirst for information and knowledge, we would find our responsibility to teach them clinical procedures to be simply work. However, their passion and excitement about learning clinical procedures for the purpose of taking care of their patients make this task a true pleasure. Finally, we would like to acknowledge our publisher for its commitment to making educational materials available to PAs and NPs. Specifically, we would like to thank Shirley Kuhn for pursuing the idea of this book with us and encouraging us to take the leap of faith necessary to publish the first edition. We would also like to thank Rolla Couchman for his help in preparing the second edition.

Chapter

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Informed Consent Ted J. Ruback

PROCEDURE GOALS

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OBJECTIVES

Goal: To provide clinicians with the necessary knowledge and understanding of the principles of informed consent for all clinical procedures. Objectives: The student will be able to …

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Describe the historical basis of informed consent.

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Describe exceptions to the requirement for informed consent.

Describe the philosophical doctrine of informed consent. Describe the underlying principles of informed consent. List the three essential conditions that must be met to ensure effective informed consent.

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Chapter 1—Informed Consent

BACKGROUND AND HISTORY OF THE PATIENT-PROVIDER RELATIONSHIP Over the last four decades, there has been a dramatic shift in the character of the physician-patient relationship, from one traditionally paternalistic or physician-focused in nature, to one that recognizes patient autonomy and is predominantly patient-centered. This struggle between paternalism and autonomy has been central to the discussions of ethically acceptable medical practice and has formed the basis for the doctrine of informed consent. Paternalism is based on the principle of beneficence, the desire to do good for the patient. The concept of informed consent asserts that the desire to do good is not a justification for overriding a competent patient’s right to personal autonomy and self-determination. Although there is some question about whether consent to medical procedures can ever be truly informed, the process of obtaining informed consent from a patient has been incorporated into American society’s expectation of good medical practice.

PURPOSE OF INFORMED CONSENT In May 2000 (amended May 2004), the House of Delegates of the American Academy of Physician Assistants adopted a policy of comprehensive “Guidelines for Ethical Conduct for the Physician Assistant Profession.” The guidelines address the profession’s responsibility in protecting a patient’s autonomy. Physician assistants have a duty to protect and foster an individual patient’s free and informed choices. The doctrine of informed consent means that a PA provides adequate information that is comprehendible to a competent patient or patient surrogate. At a minimum, this should include the nature of the medical condition, the objectives of the proposed treatment, treatment options, possible outcomes, and the risks involved. PAs should be committed to the concept of shared decision making, which involves assisting patients in making decisions that account for medical, situational, and personal factors. (American Academy of Physician Assistants, 2004) Informed consent should be obtained from a patient before all medical interventions that have the potential for harm, including diagnostic and therapeutic procedures. A patient, through the exercise of personal autonomy, may either agree to or refuse a proposed procedure or treatment, but it is the responsibility of the practitioner to make sure that the decision is based on complete and appropriate information. At the present time, the United States has no federal statute that comprehensively sets national standards of practice regarding patient consent for medical procedures. There is an implied moral obligation on professionals to disclose the necessary information to the patient, but the nature and extent

Chapter 1—Informed Consent of the legal obligation varies from one jurisdiction to another (Beauchamp, 2001). In most states, health care providers have an “affirmative duty” to disclose information regarding medical treatments, which means that information must be volunteered and not just provided in response to questions posed by the patient. Once the information has been disclosed, the provider’s obligation has been met. Weighing the risks and deciding on a course of action then becomes the responsibility of the patient or the patient’s surrogate. Legal actions against health care professionals for failure to obtain informed consent to treatment have been pursued under two separate theories of liability—one based on the concept of battery and the other on the concept of negligence (Applebaum, 1987). Most early litigation involving informed consent argued that the provision of treatment without consent constituted battery—an intentional, nonconsensual touching of the patient. The concept of battery protects a person’s physical integrity against unwanted invasion. After 1957, most suits alleging lack of informed consent were brought under the legal theory of negligence. Under this theory, an injured patient argues that he or she was harmed by the provider’s unintentional failure to satisfy a professional standard of care. When applied in an informed consent case, the alleged negligence results from a failure to disclose sufficient information about the risks or complications of a treatment.

ESSENTIAL COMPONENTS OF INFORMED CONSENT There are three essential conditions that must be met to ensure effective informed consent. First, the patient must have the capacity, or competence, to make an informed decision. A distinction is sometimes made between the medical judgment of a patient’s capacity to consent and the legal judgment of his competence; however, in clinical practice the two are closely linked (Beauchamp, 2001). Second, the patient must be given sufficient information about the procedure or treatment and the alternatives available, to allow him or her to make an informed choice. Third, the patient must give consent to treatment voluntarily, without coercion, manipulation, or duress.

PATIENT CAPACITY There is no universally accepted test of a patient’s capacity to consent to treatment. In general, an adult is presumed to be legally competent unless he or she has been formally and legally declared incompetent. Conversely, a minor is generally presumed to be legally incompetent to make medical decisions, although a number of exceptions to this rule exist and are often state-specific (e.g., emancipation). Additionally, specific legislation sometimes grants minors legal status to make some medical decisions for themselves (e.g., testing for sexually transmitted diseases, reproductive decisions).

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Chapter 1—Informed Consent Competency is usually established by assessing whether the patient has the capacity to understand the nature of his or her condition and the various options available and whether he or she is capable of making a rational decision. To make a rational choice, patients must be able to understand the treatments available and the likely outcomes in each case. They must also be able to deliberate and consider their options and weigh them against one another to choose the best alternative. To do so effectively, they must assess the options available in relation to a set of values and goals, without which they would have no basis for preferring one outcome to any other (Moskop, 1999). They must also be able to communicate their understanding and their decision in some intelligible way.

ADEQUATE INFORMATION The second requirement of informed consent is that the patient must be provided with adequate information with which to make a decision. The right to informed consent is embedded in the nature of fiduciary relationships, wherein one party has differential power, and thus that party has the inherent responsibility to share necessary information with the other. General categories of information that must be provided are the diagnosis; the nature of the proposed procedure; the risks, consequences, and benefits of the procedure; an assessment of the likelihood that the procedure(s) will accomplish the desired outcomes; and any reasonable and feasible alternatives to treatment (including the alternative of not having the procedure) and the risks and benefits of each. In clinical practice, the information required to be disclosed is frequently summarized by using the abbreviation PARQ: P (the recommended medical procedure), A (the reasonable alternatives to the recommended procedure), and R (the risks of the procedure); Q represents the additional step of asking the patient if he or she has any questions about the proposed procedure not adequately disclosed in the discussion. States are far from uniform in their views of how much information should be disclosed for meaningful informed consent. Various criteria have been proposed as both legal and moral standards for adequate disclosure. The “reasonable physician” standard bases disclosure of information on the prevailing practice within the profession. What would a typical health care provider in the same specialty and “community” disclose about this procedure? This legal standard, the only judicial standard by which courts judged physicians prior to 1972, allows the practitioner to determine what information is appropriate to disclose. It is often argued that this more paternalistic approach, although still dominant in the courts, is inconsistent with the goals of informed consent and true patient autonomy. The second standard of disclosure, introduced in 1972, is the “reasonable person” standard. The reasonable person standard requires a health care provider to disclose to a patient any material information that the practi-

Chapter 1—Informed Consent tioner recognizes that a reasonable person in the patient’s position would consider to be significant to his or her decision making about the recommended medical intervention. Risks that are not serious, or are unlikely, are not considered material. Under this standard, the critical requirement shifts from whether the disclosure met the profession’s standard to whether the undisclosed information would have been material to a reasonable patient’s decision making. The great advantage of the reasonable person standard is the focus on the preferences of the patient. A requirement for this standard is that the type and amount of information provided must be at the patient’s level of understanding if he or she is truly to be an autonomous decision maker. The disadvantages of this standard include its failure to articulate the nature of the “hypothetical” reasonable person. In addition, the retrospective application of this standard presents a significant problem in that any complication of a procedure is likely to seem material after it has occurred (Nora, 1998). Although the reasonable person standard does focus more on the patient, it does not require that the disclosure be tailored to each patient’s specific informational needs or desires. Instead, it bases the requirements on what a hypothetical reasonable person would want to know. The third standard of disclosure, the “subjective” standard, addresses this limitation by asking the question, What would this particular patient need to know and understand in order to make an informed decision? This patient-centered approach allows greater differentiation based on patient preference, relying on the unique nature and abilities of the individual patient to determine the degree of disclosure needed to satisfy the requirements of informed consent. This standard is the most challenging to implement in practice due to its requirement to tailor information specifically to each patient. In addition to providing information, the clinician has the ethical obligation to make reasonable efforts to ensure comprehension. Communicating highly technical and specialized knowledge to someone who is not conversant in the subject presents a formidable challenge. Patient-centered barriers to informed consent—such as anxiety, language differences, and physical or emotional impairments—can impede the process. Lack of familiarity or sensitivity to the patient’s cultural and health care beliefs on the part of the provider can act as a significant barrier to providing effective informed consent. Process-centered barriers, including readability of consent forms, timing of the consent discussion, and amount of time devoted to the process, also may reflect disrespect for the autonomy of the patient. To optimize information sharing, explanations should be given clearly and simply, and questions should be asked frequently to assess understanding. Whenever possible, a variety of communication techniques should be used, including written forms of educational materials, videotapes, CDs, DVDs, and additional media sources. Computers have taken on a new and everexpanding role as an effective tool in patient education when integrated into the clinical setting.

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Chapter 1—Informed Consent

VOLUNTARY CHOICE In a clinical setting, voluntariness may be influenced by the vulnerability of the patient and the inherent imbalance in knowledge and power between the health care professional and the patient. Care needs to be exercised in advising patients carefully so that what professionals construe in good faith as rational persuasion does not unintentionally exert undue influence on a patient’s decision making (Messer, 2004). Consent to treatment obtained using manipulation or coercion, or both, is the antithesis of informed consent. Although a health care provider’s recommendation regarding treatment typically can have a strong influence on a patient’s decision making, a recommendation offered as part of the clinician’s responsibility to inform and guide a patient in his or her decision making is not considered coercion.

TYPES OF INFORMED CONSENT Consent may take many forms, including implied, general, and special. Implied consent is often used when immediate action is required. In the emergency room, consent is presumed when inaction may cause greater injury or would be contrary to good medical practice. General consent is often obtained on hospital admission to provide consent for routine services and routine touching by health care staff. Such “blanket” forms generally do not list specific procedures, risks, benefits, or alternatives that might be encountered by a patient during a hospitalization. Additionally, the risk associated with a procedure may be variable depending upon a patient’s condition. Therefore, a consent to “general treatment” upon hospital admission may not be adequate to meet the requirements of informed consent (Manthous, 2003). Finally, special consent is required for specific high-risk procedures and medical treatments. State laws vary as to which interventions require a signed consent form. Some states require a written consent only for surgical interventions, anesthesia, or other more invasive procedures. Other states require informed consent be documented for a broader range of procedures. In order to ensure that informed consent is properly obtained, the health care provider should actually discuss with the patient each of the procedures to be performed, including the nature, risks, and alternatives. Consent obtained verbally is as binding as written consent because there is no legal requirement that consent be in written form; however, when disagreements arise, oral consent becomes difficult to prove. The health care provider should always document verbal consent explicitly in the medical record. Written consent is the preferred form of consent. The consent form provides legal, visible proof of a patient’s intentions. A well-drafted informed consent document can provide concrete evidence that some exchange of information was communicated to, and some assent obtained from, the patient. Such a document, supported by an entry in the patient’s medical record, is often the key to a successful malpractice defense when the issue of consent to treatment arises.

Chapter 1—Informed Consent Some states have laws that specify certain language on consent forms for certain procedures. In cases that do not require specific forms, a general consent form that identifies the patient, the date, and precise time of signature and documents the procedure, the risks associated with it, the indications, and the alternatives can be used. Most states require a consent form to be witnessed. Because of the potential conflict of interest, office personnel (nursing or other staff) should not act as the sole witness to a consent document. A written informed consent document should be prepared with the patient’s needs in mind and should verify that the patient was given the opportunity to ask questions and discuss concerns. Consent forms are often written in great detail and use medical and legal terminology that is far beyond the capacity of many patients. For true autonomy to exist in informed consent, consent forms should be understandable and should include the patient’s primary language or languages whenever possible. When appropriate, an interpreter should be made available during the informed consent conference. The issue of comprehension is vital to the process. Health care providers should not make the mistake of equating the written and signed document with informed consent. The provider should always take care to make sure that information-transferring communication did occur.

PATIENT’S RIGHT TO REFUSE TREATMENT Patients have the right to refuse treatment. In such circumstances, it is essential to document carefully such refusals and, most importantly, the patient’s understanding of the potential consequences of refusing treatment. The signature of a witness is helpful in these circumstances.

EXCEPTIONS TO INFORMED CONSENT REQUIREMENTS Several types of legitimate exceptions to the right of informed consent have been described. In rare instances, courts have recognized limited privileges that potentially can protect health care providers from claims alleging a lack of informed consent. Such exceptions include emergencies, patients unable to consent, a patient waiver of consent, public health requirements, and therapeutic privilege. In all these instances, the provider has the burden of proving that the claimed exception was invoked appropriately. According to the emergency exception, if treatment is required to prevent death or other serious harm to a patient, that treatment may be provided without informed consent. Courts have upheld that the emergent nature of the situation and the impracticality of conferring with the patient preclude the need for informed consent. This exception is based on the presumption that the patient would consent to treatment to preserve life or health if he or

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Chapter 1—Informed Consent she were able to do so and if there were sufficient time to obtain consent. Despite this exception, a competent patient may refuse interventions even if they are life-saving. For example, courts have repeatedly recognized the rights of Jehovah’s Witnesses to refuse blood products. Care of patients who lack decision-making capacity can be provided without the patient’s informed consent. This exception, however, does not imply that no consent is necessary; instead, informed consent is required from a surrogate acting on behalf of the patient. Some surrogate decision makers are clearly identifiable (e.g., the legal guardians assigned to protect the best interests of persons judged to be incompetent and the parents of minor children). In other cases, surrogates are more difficult to determine. The decision-making authority of surrogates is directed by defined standards. These standards require surrogates to rely first on any treatment preferences specifically indicated by the patient, either written or oral, before he or she lost decision-making capacity. Lacking such direction, surrogates are then empowered to exercise “substituted judgment,”—that is, to use their knowledge of the patient’s preferences and values to choose the alternative they believe the patient would choose if he or she were able to do so. In some instances, prior knowledge of a patient’s preferences or values is lacking. In such situations, surrogates are directed to rely on their assessment of the patient’s best interests and are encouraged to pursue the course of action they deem most likely to foster the patient’s overall well-being (Buchanan, 1989). When a surrogate’s treatment choice appears clearly contrary to a patient’s previously expressed wishes or best interests, the patient’s provider is dutybound to question that choice. The health care provider does not have the authority to unilaterally override the surrogate’s decision but must bring the issue to the attention of an appropriate legal authority for review and adjudication. In the “Guidelines for Ethical Conduct for the Physician Assistant Profession,” the clinician’s role with regard to surrogates is clearly delineated. When the person giving consent is a patient’s surrogate, a family member, or other legally authorized representative, the PA should take reasonable care to assure that the decisions made are consistent with the patient’s best interests and personal preferences, if known. If the PA believes the surrogate’s choices do not reflect the patient’s wishes or best interests, the PA should work to resolve the conflict. This may require the use of additional resources, such as an ethics committee. (American Academy of Physician Assistants, 2004) Informed consent, although clearly recognized as a patient’s right, is not a patient’s duty. Patients can choose to waive their right to receive the relevant information and give informed consent to treatment. The provider may honor the patient’s right to choose someone else to make treatment decisions on his or her behalf as long as the request is made competently, voluntarily, and with some understanding that the patient recognizes that he or she is relinquishing a right. Health care providers should not feel obligated to

Chapter 1—Informed Consent accept the responsibility for making treatment decisions for the patient if they are asked to do so. Instead, they can request that the patient make his or her own choice or designate another person to serve as surrogate. Sometimes medical interventions have a potential benefit not only to the patient but also to others in the community. In such rare instances, public health statutes may authorize patient detention or treatment without the patient’s consent. This exception overrides individual patient autonomy in specific circumstances to protect important public health interests. The final exception to informed consent is the concept of therapeutic privilege, which allows the health care provider to let considerations about the physical, mental, and emotional state of the patient affect what information is disclosed to the patient. The practitioner should believe that the risk of giving information would pose a serious detriment to the patient. The anticipated harm must result from the disclosure itself and not from the potential influence that the information might have on the patient’s choice. The sole justification of concern that the patient might refuse needed therapy is not considered adequate to justify invoking this exception. The therapeutic privilege is extremely controversial and not universally recognized. Thus, the value of therapeutic privilege as an independent exception to informed consent is limited.

CONCLUSIONS The moral and legal doctrine of informed consent and its counterpart, the refusal of treatment, are products of the last half of the 20th century. During this time, judges sought to protect patient autonomy—that is, the patient’s right to self-determination. Informed consent requires the health care practitioner to provide the patient with an adequate disclosure and explanation of the treatment and the various options and consequences. Informed consent, however, is more than a legal necessity. When conducted properly, the process of communicating appropriate information to patients about treatment alternatives can help establish a reciprocal relationship between health care provider and patient that is based on good and appropriate communication, considered advice, mutual respect, and rational choices. The therapeutic objective of informed consent should be to replace some of the patient’s anxiety and unease with a sense of participation as a partner in decision making. Such a sense of participation strengthens the therapeutic alliance between provider and patient. After initial consent to treatment has occurred, a continuing dialogue between patient and practitioner, based on the patient’s continuing medical needs, reinforces the original consent. In the event of an unfavorable outcome, the enhanced relationship will prove crucial to maintaining the patient’s trust. In the area of informed consent, as in every other area of risk management, the best recommendation is to practice good medicine. Informed consent is an essential part of good medical practice today and is an ethical and moral responsibility of all health care providers.

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Chapter 1—Informed Consent

REFERENCES American Academy of Physician Assistants: Guidelines for Ethical Conduct for the Physician Assistant Profession. Alexandria, Va, American Academy of Physician Assistants, 2004. Applebaum PS, Lidz CW, Meisel A: Informed Consent: Legal Theory and Clinical Practice. New York, Oxford University Press, 1987. Beauchamp TL, Childress JF: Principles of Biomedical Ethics, 5th ed. New York, Oxford University Press, 2001. Buchanan AE, Brock DW: Deciding for Others: The Ethics of Surrogate Decision Making. Cambridge, England, Cambridge University Press, 1989. Manthous CA, DeFirolamo A, Haddad C, Amoateng-Adjepong Y: Informed consent for medical procedures: local and national practices. Chest 124:1978-1984, 2003. Messer NG: Professional-patient relationships and informed consent. Postgrad Med J 80:277-283, 2004. Moskop JC: Informed consent in the emergency department. Emerg Clin N Am 17:327-340, 1999. Nora LM, Benvenuti RJ: Medicolegal aspects of informed consent. Neurol Clin N Am 16:207-215, 1998.

BIBLIOGRAPHY Jonsen AR, Siegler M, Winslade WJ: Clinical Ethics, 4th ed. New York, McGraw-Hill, 1998. Mazur DJ: Medical Risk and the Right to an Informed Consent in Clinical Care and Clinical Research. Tampa, Fla, American College of Physician Executives, 1998. Mazur DJ: Shared Decision Making in the Patient-Physician Relationship. Tampa, Fla, American College of Physician Executives, 2001.

Chapter

2

Standard Precautions Kirsten Thomsen

PROCEDURE GOALS

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OBJECTIVES

Goal: To use and understand the importance of standard precautions when interacting with a patient. Objectives: The student will be able to …

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Describe the indications, contraindications, and rationale for adhering to standard precautions.

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Identify and describe common problems associated with adhering to standard precautions.

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Describe the essential infectious disease principles associated with standard precautions.

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Identify the materials necessary for adhering to standard precautions and their proper use.

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Chapter 2—Standard Precautions

BACKGROUND AND HISTORY The concept of isolating patients with infectious diseases in separate facilities, which became known as infectious disease hospitals, was introduced in a published hospital handbook as early as 1877. Although infected and noninfected patients were separated, nosocomial transmission continued, largely because of the lack of minimal aseptic procedures, coupled with the fact that infected patients were not separated from each other by disease. By 1890 to 1900, nursing textbooks discussed recommendations for practicing aseptic procedures and designating separate floors or wards for patients with similar diseases, thereby beginning to solve the problems of nosocomial transmission (Lynch, 1949). Shortly thereafter, the cubicle system of isolation changed U.S. hospital isolation procedures as patients were placed in multiple-bed wards. “Barrier nursing” practices, consisting of the use of aseptic solutions, hand washing between patient contacts, disinfecting patient-contaminated objects, and separate gown use, were developed to decrease pathogenic organism transmission to other patients and personnel. These practices were used in U.S. infectious disease hospitals. By the 1960s, the designation of specifically designed single- or multiple-patient isolation rooms in general hospitals and outpatient treatment for tuberculosis caused these specialized hospitals (which since the 1950s had housed tuberculosis patients almost exclusively) to close (Garner, 1996). The lack of consistent infectious patient isolation policies and procedures noted by the Centers for Disease Control (CDC) investigators in the 1960s led to the CDC publication in 1970 of a detailed isolation precautions manual entitled Isolation Techniques for Use in Hospitals, designed to assist large metropolitan medical centers as well as small hospitals with limited budgets. After revision in 1983, the manual was renamed the CDC Guidelines for Isolation Precautions in Hospitals. These new guidelines encouraged hospital infection control decision making with respect to developing isolation systems specific to the hospital environment and circumstances or choosing to select between category-specific or disease-specific isolation precautions. Decisions regarding individual patient precautions were to be based on factors such as patient age, mental status, or possible need to prevent sharing of contaminated articles and were to be determined by the individual who placed the patient on isolation status. Decisions regarding the need for decreasing exposure to infected material by wearing masks, gloves, or gown were to be left to the patient caregiver (Garner, 1984; Haley, 1985). Issues of overisolation of some patients surfaced using the 1983 categories of isolation, which included strict isolation, contact isolation, respiratory isolation, tuberculosis (acid-fast bacilli) isolation, enteric precautions, drainage-secretion precautions, and blood and body fluid precautions. In using the disease-specific isolation precautions, the issue of mistakes in applying the precautions arose if the patient carried a disease not often seen or treated in the hospital (Garner, 1984; Haley, 1985), if the diagnosis was delayed, or if a misdiagnosis occurred. This happened even if additional

Chapter 2—Standard Precautions training of personnel was encouraged. These factors, coupled with increased knowledge of epidemiologic patterns of disease, led to subsequent updates of portions of the CDC reports: ■

Recommendations for the management of patients with suspected hemorrhagic fever published in 1988 (CDC, 1988)

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Recommendations for respiratory isolation for human parvovirus B19 infection specific to patients who were immunodeficient and had chronic human parvovirus B19 infection or were in transient aplastic crisis (CDC, 1989)

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Recommendations for the management of tuberculosis, which stemmed from increasing concern for multidrug-resistant tuberculosis, especially in human immunodeficiency virus (HIV)–infected patients in care facilities (CDC, 1990)

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Recommendations for hantavirus infection risk reduction (CDC, 1994)

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Expansion of recommendations for the prevention and control of hepatitis C virus (HCV) infection and hepatitis C virus–related chronic disease (CDC, 1998)

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Occupational exposure recommendations and postexposure management for hepatitis B virus (HBV), HCV, and HIV (CDC, 2001)

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Recommendations for infection control of avian influenza and management of exposure to severe acute respiratory syndrome–associated coronavirus (SARS-CoV) in the healthcare setting (CDC, 2004; CDC, 2005)

BODY SUBSTANCE ISOLATION An entirely different approach to isolation, called body substance isolation (BSI), was developed in 1984 by Lynch and colleagues (1987, 1990) and required personnel, regardless of patient infection status, to apply clean gloves immediately before all patient contact with mucous membranes or nonintact skin, and to wear gloves if a likelihood existed of contact with any moist body substances. An apron or other barrier was also to be worn to keep the provider’s own clothing and skin clean. It was recommended also that personnel be immunized if proof of immunity could not be documented when barriers, such as masks, could not prevent transmission by airborne routes (e.g., rubella, chickenpox). Additionally, when immunity was not possible, as with pulmonary tuberculosis, masks were to be worn during all patient contact. Goggles or glasses, hair covers, and shoe covers were also used as barriers. Careful handling of all used sharps, recapping of needles without using the hands, and the disposal of used items in rigid punctureresistant containers were stressed. Trash and soiled linen from all patients were bagged and handled in the same manner. This approach sought to protect the patient from contracting nosocomial infections and the provider from bacterial or viral pathogens that might originate with the patient.

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Chapter 2—Standard Precautions

UNIVERSAL PRECAUTIONS In response to increasing concerns by health care workers and others about occupational exposure and the risk of transmission of human immunodeficiency virus, HBV, and other blood-borne pathogens during provision of health care and first aid, the CDC, in 1987, defined a set of precautions that considered blood and certain body fluids from all patients to be potential sources of infection for human immunodeficiency virus, HBV, and other blood-borne pathogens. These recommendations became known as universal precautions (UP) and have subsequently been integrated into the Recommendations for Isolation Precautions in Hospitals, 1996, which includes the current standard precautions (SP) (Table 2-1). Recommendations for Isolation Precautions in Hospitals, Hospital Infection Control Practices Advisory Committee, 1996

Table 2.1

STANDARD PRECAUTIONS Use Standard Precautions, or the equivalent, for the care of all patients. HAND WASHING Wash hands after touching blood, body fluids, secretions, excretions, and contaminated items, whether or not gloves are worn. Wash hands immediately after gloves are removed, between patient contacts, and when otherwise indicated to avoid transfer of microorganisms to other patients or environments. It may be necessary to wash hands between tasks and procedures on the same patient to prevent cross-contamination of different body sites. Use a plain (nonantimicrobial) soap for routine hand washing. Use an antimicrobial agent or a waterless antiseptic agent for specific circumstances (e.g., control of outbreaks or hyperendemic infections), as defined by the infection control program. (See “Contact Precautions” for additional recommendations on using antimicrobial and antiseptic agents.) GLOVES Wear gloves (clean, nonsterile gloves are adequate) when touching blood, body fluids, secretions, excretions, and contaminated items. Put on clean gloves just before touching mucous membranes and nonintact skin. Change gloves between tasks and procedures on the same patient after contact with material that may contain a high concentration of microorganisms. Remove gloves promptly after use, before touching noncontaminated items and environmental surfaces, and before going to another patient, and wash hands immediately to avoid transfer of microorganisms to other patients or environments. MASK, EYE PROTECTION, FACE SHIELD Wear a mask and eye protection or a face shield to protect mucous membranes of the eyes, nose, and mouth during procedures and patient care activities that are likely to generate splashes or sprays of blood, body fluids, secretions, and excretions. GOWN Wear a gown (a clean, nonsterile gown is adequate) to protect skin and to prevent soiling of clothing during procedures and patient care activities that are likely to generate splashes or sprays of blood, body fluids, secretions, or excretions. Select a gown that is appropriate for the activity and amount of fluid likely to be encountered. Remove a soiled gown as promptly as possible, and wash hands to avoid transfer of microorganisms to other patients or environments. PATIENT CARE EQUIPMENT Handle used patient care equipment soiled with blood, body fluids, secretions, and excretions in a manner that prevents skin and mucous membrane exposures, contamination of clothing,

Chapter 2—Standard Precautions Recommendations for Isolation Precautions in Hospitals, Hospital Infection Control Practices Advisory Committee, 1996—cont’d

Table 2.1

and transfer of microorganisms to other patients and environments. Ensure that reusable equipment is not used for the care of another patient until it has been cleaned and reprocessed appropriately. Ensure that single-use items are discarded properly. ENVIRONMENTAL CONTROL Ensure that the hospital has adequate procedures for the routine care, cleaning, and disinfection of environmental surfaces, beds, bed rails, bedside equipment, and other frequently touched surfaces, and ensure that these procedures are being followed. LINEN Handle, transport, and process used linen soiled with blood, body fluids, secretions, and excretions in a manner that prevents skin and mucous membrane exposures and contamination of clothing, and that avoids transfer of microorganisms to other patients and environments. OCCUPATIONAL HEALTH AND BLOOD-BORNE PATHOGENS Take care to prevent injuries when using needles, scalpels, and other sharp instruments or devices; when handling sharp instruments after procedures; when cleaning used instruments; and when disposing of used needles. Never recap used needles, or otherwise manipulate them using both hands, or use any other technique that involves directing the point of a needle toward any part of the body; rather, use either a one-handed “scoop” technique or a mechanical device designed for holding the needle sheath. Do not remove used needles from disposable syringes by hand, and do not bend, break, or otherwise manipulate used needles by hand. Place used disposable syringes and needles, scalpel blades, and other sharp items in appropriate puncture-resistant containers, which are located as close as is practical to the area in which the items were used, and place reusable syringes and needles in a punctureresistant container for transport to the reprocessing area. Use mouthpieces, resuscitation bags, or other ventilation devices as an alternative to mouth-to-mouth resuscitation methods in areas where the need for resuscitation is predictable. PATIENT PLACEMENT Place a patient who contaminates the environment or who does not (or cannot be expected to) assist in maintaining appropriate hygiene or environmental control in a private room. If a private room is not available, consult with infection control professionals regarding patient placement or other alternatives. AIRBORNE PRECAUTIONS In addition to standard precautions, use airborne precautions, or the equivalent, for patients known or suspected to be infected with microorganisms transmitted by airborne droplet nuclei (small-particle residue [5 μm or smaller in size] of evaporated droplets containing microorganisms that remain suspended in the air and that can be dispersed widely by air currents within a room or over a long distance). PATIENT PLACEMENT Place the patient in a private room that has (1) monitored negative air pressure in relation to the surrounding area, (2) six to twelve air changes per hour, and (3) appropriate discharge of air outdoors or monitored high-efficiency filtration of room air before the air is circulated to other areas in the hospital. Keep the room door closed and the patient in the room. When a private room is not available, place the patient in a room with a patient who has active infection with the same microorganism, unless otherwise recommended, but with no other infection. When a private room is not available and cohorting is not desirable, consultation with infection control professionals is advised before patient placement. RESPIRATORY PROTECTION Wear respiratory protection when entering the room of a patient with known or suspected infectious pulmonary tuberculosis. Susceptible persons should not enter the room of patients known or suspected to have measles (rubeola) or varicella (chickenpox) if other, immune caregivers are available. If susceptible persons must enter the room of a patient known or continued

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Chapter 2—Standard Precautions Recommendations for Isolation Precautions in Hospitals, Hospital Infection Control Practices Advisory Committee, 1996—cont’d

Table 2.1

suspected to have measles (rubeola) or varicella, they should wear respiratory protection. Persons immune to measles (rubeola) or varicella need not wear respiratory protection. PATIENT TRANSPORT Limit the movement and transport of the patient from the room to essential purposes only. If transport or movement is necessary, minimize patient dispersal of droplet nuclei by placing a surgical mask on the patient, if possible. ADDITIONAL PRECAUTIONS FOR PREVENTING TRANSMISSION OF TUBERCULOSIS Consult CDC Guidelines for Preventing the Transmission of Tuberculosis in Health Care Facilities for additional prevention strategies. DROPLET PRECAUTIONS In addition to standard precautions, use droplet precautions, or the equivalent, for a patient known or suspected to be infected with microorganisms transmitted by droplets (large-particle droplets [larger than 5 μm in size] that can be generated by the patient during coughing, sneezing, talking, or the performance of procedures). PATIENT PLACEMENT Place the patient in a private room. When a private room is not available, place the patient in a room with a patient(s) who has active infection with the same microorganism but with no other infection (cohorting). When a private room is not available and cohorting is not achievable, maintain spatial separation of at least 3 feet between the infected patient and other patients and visitors. Special air handling and ventilation are not necessary, and the door may remain open. MASK In addition to standard precautions, wear a mask when working within 3 feet of the patient. (Logistically, some hospitals may want to implement the wearing of a mask to enter the room.) PATIENT TRANSPORT Limit the movement and transport of the patient from the room to essential purposes only. If transport or movement is necessary, minimize patient dispersal of droplets by masking the patient, if possible. CONTACT PRECAUTIONS In addition to standard precautions, use contact precautions, or the equivalent, for specified patients known or suspected to be infected or colonized with epidemiologically important microorganisms that can be transmitted by direct contact with the patient (hand or skin-toskin contact that occurs when performing patient care activities that require touching the patient’s dry skin) or indirect contact (touching) with environmental surfaces or patient care items in the patient’s environment. PATIENT PLACEMENT Place the patient in a private room. When a private room is not available, place the patient in a room with a patient(s) who has active infection with the same microorganism but with no other infection (cohorting). When a private room is not available and cohorting is not achievable, consider the epidemiology of the microorganism and the patient population when determining patient placement. Consultation with infection control professionals is advised before patient placement. GLOVES AND HAND WASHING In addition to wearing gloves as outlined under “Standard Precautions,” wear gloves (clean, nonsterile gloves are adequate) when entering the room. During the course of providing care for a patient, change gloves after having contact with infective material that may contain high concentrations of microorganisms (fecal material and wound drainage). Remove gloves before leaving the patient’s environment and wash hands immediately with an antimicrobial agent or

Chapter 2—Standard Precautions Recommendations for Isolation Precautions in Hospitals, Hospital Infection Control Practices Advisory Committee, 1996—cont’d

Table 2.1

a waterless antiseptic agent. After glove removal and hand washing, ensure that hands do not touch potentially contaminated environmental surfaces or items in the patient’s room to avoid transfer of microorganisms to other patients or environments. GOWN In addition to wearing a gown as outlined under “Standard Precautions,” wear a gown (a clean, nonsterile gown is adequate) when entering the room if you anticipate that your clothing will have substantial contact with the patient, environmental surfaces, or items in the patient’s room, or if the patient is incontinent or has diarrhea, an ileostomy, a colostomy, or wound drainage not contained by a dressing. Remove the gown before leaving the patient’s environment. After gown removal, ensure that clothing does not contact potentially contaminated environmental surfaces to avoid transfer of microorganisms to other patients or environments. PATIENT TRANSPORT Limit the movement and transport of the patient from the room to essential purposes only. If the patient is transported out of the room, ensure that precautions are maintained to minimize the risk of transmission of microorganisms to other patients and contamination of environmental surfaces or equipment. PATIENT CARE EQUIPMENT When possible, dedicate the use of noncritical patient care equipment to a single patient (or cohort of patients infected or colonized with the pathogen requiring precautions) to avoid sharing between patients. If use of common equipment or items is unavoidable, adequately clean and disinfect them before use for another patient. ADDITIONAL PRECAUTIONS FOR PREVENTING THE SPREAD OF VANCOMYCIN RESISTANCE Consult the HICPAC report on preventing the spread of vancomycin resistance for additional prevention strategies. HICPAC, Hospital Infection Control Practices Advisory Committee. From Centers for Disease Control and Prevention: Recommendations for Isolation Precautions in Hospitals, 1996. Available at: http://www.cdc.gov/ncidod/hip/isolat/isopart1.htm and www.cdc.gov./ncidod/hip/isolat/isopart2.htm

STANDARD PRECAUTIONS Although universal precautions were designed to address the transmission of blood-borne infections through blood and certain body fluids, they do not address other routes of disease transmission, which were addressed at the time by body substance isolation guidelines. Additionally, confusion developed as to whether one should use universal precautions and body substance isolation guidelines, because both guidelines dealt with similar circumstances but offered conflicting recommendations. The guideline for isolation precautions in hospitals was revised in 1996 by the CDC and the Hospital Infection Control Practices Advisory Committee (HICPAC), which had been established in 1991 to serve in a guiding and advisory capacity to the Secretary of the Department of Health and Human Services (DHHS), the Assistant Secretary of Health of the DHHS, the Director of the CDC, and the Director of the National Center for Infectious Diseases with respect to hospital infection

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Chapter 2—Standard Precautions control practices and U.S. hospital surveillance, prevention, and control strategies for nosocomial infections. The CDC guideline revision was designed to include the following objectives: (1) to be epidemiologically sound; (2) to recognize the importance of all body fluids, secretions, and excretions in the transmission of nosocomial pathogens; (3) to contain adequate precautions for infections transmitted by the airborne, droplet, and contact routes of transmission; (4) to be as simple and user friendly as possible; and (5) to use new terms to avoid confusion with existing infection control and isolation systems. (Garner, 1996) The new guidelines were designed to supersede universal precautions and body substance isolation guidelines and in essence combined parts of both these previous guidelines. This synthesis of guidelines allows patients who were previously covered under disease-specific guidelines to now fall under standard precautions, a single set of recommendations. For patients who require additional precautions (defined as transmission-based precautions, for use when additional transmission risk exists [e.g., from airborne or droplet contamination]), additional guidelines have been developed to go above and beyond those of standard precautions (Garner, 1996) (see Table 2-1).

GLOVES, GOWNS, MASKS, AND OTHER PROTECTIVE BARRIERS AS PART OF UNIVERSAL PRECAUTIONS All health care workers should routinely use appropriate barrier precautions to prevent skin and mucous membrane exposure during contact with any patient’s blood or body fluids that require universal precautions. Gloves should be worn as follows: ■ For touching blood and body fluids requiring universal precautions, mucous membranes, or nonintact skin of all patients ■

For handling items or surfaces soiled with blood or body fluids to which universal precautions apply

Gloves should be changed after contact with each patient. Hands and other skin surfaces should be washed immediately or as soon as patient safety permits if contaminated with blood or body fluids requiring universal precautions. Hands should be washed immediately after gloves are removed. Gloves should reduce the incidence of blood contamination of hands during phlebotomy, but they cannot prevent penetrating injuries caused by needles or other sharp instruments. Institutions that judge routine gloving for all phlebotomies as not necessary should periodically re-evaluate their policy. Gloves should always be available to health care workers who wish to use them for phlebotomy. In addition, the following general guidelines apply: ■ Use gloves for performing phlebotomy when the health care worker has cuts, scratches, or other breaks in the skin.

Chapter 2—Standard Precautions ■

Use gloves in situations in which the health care worker judges that hand contamination with blood may occur; for example, when performing phlebotomy in an uncooperative patient.

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Use gloves for performing finger or heel sticks, or both, in infants and children.

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Use gloves when persons are receiving training in phlebotomy.

Masks and protective eyewear or face shields should be worn by health care workers to prevent exposure of mucous membranes of the mouth, nose, and eyes during procedures that are likely to generate droplets of blood or body fluids requiring universal precautions. Gowns or aprons should be worn during procedures that are likely to generate splashes of blood or body fluids requiring universal precautions. All health care workers should take precautions to prevent injuries caused by needles, scalpels, and other sharp instruments or devices during procedures; when cleaning used instruments; during disposal of used needles; and when handling sharp instruments after procedures. To prevent needlestick injuries, needles should not be recapped by hand, purposely bent or broken by hand, removed from disposable syringes, or otherwise manipulated by hand. After they are used, disposable syringes and needles, scalpel blades, and other sharp items should be placed in puncture-resistant containers for disposal. The puncture-resistant containers should be located as close as is practical to the area of use. All reusable needles should be placed in puncture-resistant containers for transport to the reprocessing area. General infection control practices should further minimize the already minute risk for salivary transmission of human immunodeficiency virus. These infection control practices include the use of gloves for digital examination of mucous membranes and endotracheal suctioning, hand washing after exposure to saliva, and minimizing the need for emergency mouth-to-mouth resuscitation by making mouthpieces and other ventilation devices available for use in areas where the need for resuscitation is predictable.

THE APPLICATION OF STANDARD PRECAUTIONS IN CLINICAL PROCEDURES Standard precautions should be followed when performing any procedure in which exposure to, or transmission of, infectious agents is possible. These guidelines attempt to minimize exposure to infectious body fluids. Because it is not always possible to determine in advance whether a specific patient is infectious, these precautions should be followed routinely for all patients. The nature of performing clinical procedures often results in exposure to body fluids. Consequently, as practitioners involved in performing clinical procedures, it is imperative that we attempt to anticipate potential exposures and implement preventive guidelines to reduce exposure risks.

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Chapter 2—Standard Precautions Additionally, it is important that the practitioner assess the health status of each patient to determine if additional precautions are warranted and, if so, apply the necessary transmission-based precautions as described in Table 2-1. Standard precautions are the current recommended behaviors designed to prevent the transmission of pathogens from patient to practitioner or practitioner to patient. It is imperative that all providers be knowledgable about standard precautions and transmission-based precautions and how to practice them competently and consistently.

REFERENCES Centers for Disease Control and Prevention: Interim recommendations for infection control in health-care facillities caring for patients with known or suspected avian influenza. May 21, 2004. Available at http://www.cdc.gov/flu/avian/professional/infect-control.htm, accessed 7/3/06. Centers for Disease Control and Prevention: Public health guidance for community-level preparedness and response to severe acute respiratory syndrome (SARS) version 2. Supplement I: Infection control in healthcare, home, and community setting. May 3, 2005. Available at http://www.cdc.gov/ncidod/sars/guidance/i/, accessed 7/3/06. Centers for Disease Control and Prevention: Updated U.S. Public Health Service guidelines for the management of occupational exposures to HBV, HCV, and HIV and recommendations for postexposure prophylaxis. MMWR Morb Mortal Wkly Rep 50:1-42, 2001. Centers for Disease Control and Prevention: Recommendations for prevention and control of hepatitis C virus (HCV) infection and HCV-related chronic disease. MMWR Morb Mortal Wkly Rep 47:1-39, 1998. Centers for Disease Control and Prevention: Laboratory management of agents associated with hantavirus pulmonary syndrome: Interim biosafety guidelines. MMWR Morb Mortal Wkly Rep 43:1-7, 1994. Centers for Disease Control: Guidelines for preventing the transmission of tuberculosis in health-care settings, with special focus on HIV-related issues. MMWR Morb Mortal Wkly Rep 39:1-29, 1990. Centers for Disease Control: Risks associated with human parvovirus B19 infection. MMWR Morb Mortal Wkly Rep 38:81-88, 93-97, 1989. Centers for Disease Control: Management of patients with suspected viral hemorrhagic fever. MMWR Morb Mortal Wkly Rep 37:1-16, 1988. Centers for Disease Control: Update: Universal precautions for prevention of transmission of human immunodeficiency virus, hepatitis B virus, and other blood borne pathogens in health-care settings. MMWR Morb Mortal Wkly Rep 37:377-388, 1988. Garner JS: Guideline for isolation precautions in hospitals. Part I. Evolution of isolation practices, Hospital Infection Control Practices Advisory Committee. Am J Infect Control 24:24-31, 1996. Garner JS: Comments on CDC guideline for isolation precautions in hospitals, 1984. Am J Infect Control 12:163-164, 1984. Haley RW, Garner JS, Simmons BP: A new approach to the isolation of patients with infectious diseases: Alternative systems. J Hosp Infect 6:128-139, 1985.

Chapter 2—Standard Precautions Lynch P, Cummings MJ, Roberts PL: Implementing and evaluating a system of generic infection precautions: Body substance isolation. Am J Infect Control 18:1-12, 1990. Lynch P, Jackson MM: Rethinking the role of isolation precautions in the prevention of nosocomial infections. Ann Intern Med 107:243-246, 1987. Lynch T: Communicable Disease Nursing. St. Louis, CV Mosby, 1949.

BIBLIOGRAPHY American College of Physicians Task Force on Adult Immunization and Infectious Diseases Society of America: Guide for Adult Immunization, 3rd ed. Philadelphia, American College of Physicians, 1994. Bell DM, Shapiro CN, Ciesielski CA, Chamberland ME: Preventing blood borne pathogen transmission from health care workers to patients: The CDC perspective. Surg Clin North Am 75:1189-1203, 1995. Cardo DM, Culver DH, Ciesielski CA, et al: A case-control study of HIV seroconversion in health care workers after percutaneous exposure: Centers for Disease Control and Prevention Needlestick Surveillance Group. N Engl J Med 337:1485-1490, 1997. Centers for Disease Control and Prevention: Public Health Service (PHS) guidelines for the management of health care worker exposures to HIV and recommendations for postexposure prophylaxis. MMWR Morb Mortal Wkly Rep 47:1-33, 1998. Centers for Disease Control and Prevention: Immunization of health-care workers: Recommendations of the Advisory Committee on Immunization Practices (ACIP) and the Hospital Infection Control Practices Advisory Committee (HICPAC). MMWR Morb Mortal Wkly Rep 46:1-42, 1997. Centers for Disease Control and Prevention: Recommendations for follow-up of health-care workers after occupational exposure to hepatitis C virus. MMWR Morb Mortal Wkly Rep 46:603-606, 1997. Centers for Disease Control and Prevention: Case-control study of HIV seroconversion in health-care workers after percutaneous exposure to HIV infected blood—France, United Kingdom, and United States, January 1988-August 1994. MMWR Morb Mortal Wkly Rep 44:929-933, 1995. Centers for Disease Control and Prevention: Hospital Infection Control Practices Advisory Committee: Guideline for prevention of nosocomial pneumonia. Infect Control Hosp Epidemiol 15:587-627, 1994. Centers for Disease Control and Prevention: Guidelines for preventing the transmission of Mycobacterium tuberculosis in health-care facilities, 1994. MMWR Morb Mortal Wkly Rep 43:1-132, 1994. Centers for Disease Control and Prevention: National Institutes for Health: Biosafety in Microbiological and Biomedical Laboratories, 3rd ed. Atlanta, U.S. Department of Health and Human Services, Public Health Service, 1993. Centers for Disease Control and Prevention: Update on adult immunization: Recommendations of the Immunization Practices Advisory Committee (ACIP). MMWR Morb Mortal Wkly Rep 40:1-94, 1991. Centers for Disease Control and Prevention: Protection against viral hepatitis: Recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Morb Mortal Wkly Rep 39:1-27, 1990.

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Chapter 2—Standard Precautions Chin J (ed): Control of Communicable Diseases Manual, 17th ed. Washington, DC, American Public Health Association, 1999. Diekema DJ, Alabanese MA, Schuldt SS, Doebbeling BN: Blood and body fluid exposures during clinical training: Relation to knowledge of universal precautions. J Gen Intern Med 11:109-111, 1996. Garner JS: Hospital Infection Control Practices Advisory Committee: Guidelines for Isolation Precautions in Hospitals. Infect Control Hosp Epidemiol 17:53-80, 1996. Gerberding JL, Lewis FR Jr, Schecter WP: Are universal precautions realistic? Surg Clin North Am 75:1091-1104, 1995. Moran G: Emergency department management of blood and fluid exposures. Ann Emerg Med 35:47-62, 2000. National Committee for Clinical Laboratory Standards: Protection of laboratory workers from infectious disease transmitted by blood, body fluids, and tissue: Tentative guideline. NCCLS Document M29T2, vol 11. Villanova, Pa, National Committee for Clinical Laboratory Standards, 1991, pp 1-214. Orenstein R, Reynolds L, Karabaic M, et al: Do protective devices prevent needlestick injuries among health care workers? Am J Infect Control 23:344-351, 1995. Osborn EH, Papadakis MA, Gerberding JL: Occupational exposures to body fluids among medical students: A seven-year longitudinal study. Ann Intern Med 130:45-51, 1999. Peter G (ed): Report of the Committee on Infectious Diseases Red Book, 25th ed. Elk Grove Village, Ill, American Academy of Pediatrics, 2000. U.S. Department of Labor, Occupational Health and Safety Administration: Criteria for recording on OSHA Form 200. OSHA instruction 1993, standard 1904. Washington, DC, U.S. Department of Labor, 1993. U.S. Department of Labor, Occupational Safety and Health Administration: Occupational exposure to blood borne pathogens, final rule. CFR Part 1910.1030. Fed Reg 56:64004-64182, 1991. U.S. Department of Labor, Occupational Health and Safety Administration: Record keeping guidelines for occupational injuries and illnesses: The Occupational Safety and Health Act of 1970 and 29 CFR 1904. OMB No. 120-0029. Washington, DC, U.S. Department of Labor, 1986.

Chapter

3

Sterile Technique Paul C. Hendrix

PROCEDURE GOALS

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OBJECTIVES

Goal: To provide clinicians with the knowledge and skills necessary to perform clinical procedures using accepted sterile technique. Objectives: The student will be able to …

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Describe the indications and rationale for practicing sterile technique.

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Identify and describe the history and development of the concept of sterile technique.

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List the principles of sterile technique.

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Describe the principles involved in the use of surgical caps, masks, and gowns.

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Describe the principles involved in the use of standard precautions.

Describe the essential steps performed in the surgical hand scrub. Describe the essential steps performed in preparing and draping a sterile field.

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Chapter 3—Sterile Technique

BACKGROUND AND HISTORY The teachings of Hippocrates (460 BC) were instrumental in turning the art of healing away from mystical rites to an approach that everyone could understand and practice. He stressed cleanliness to avoid infection by using boiling water and fire to clean instruments and by irrigating dirty wounds with wine or boiled water (Adams, 1929). Louis Pasteur (1822-1895) developed what would come to be known as the germ theory of disease. His experiments revealed that microbes could be found in the air and on the surface of every object (Dubos, 1950). He discovered that the number of microbes could be reduced on surfaces by using heat or appropriate cleansing but that they would still remain in the air. Joseph Lister (1827-1912) is considered the father of sterile technique (Godlee, 1917). When Lister learned of Pasteur’s work, he began to experiment with various methods of sterile technique in surgery. He noted a significant decrease in postoperative infections after using carbolic acid to sterilize both surgical wounds and his own hands and by spraying the operative field. His antiseptic methods of performing surgery were refined over the years and eventually incorporated into hospitals worldwide.

PRINCIPLES OF STERILE TECHNIQUE Sterile technique is the method by which contamination with microorganisms is minimized. Adherence to protocol and strict techniques is required at all times when caring for open wounds and performing invasive procedures. To avoid infection, procedures should be performed within a sterile field from which all living microbes have been excluded. Items entering the sterile field, including instruments, sutures, and fluids, must be sterile. Although it is not possible to sterilize the skin, it is possible to reduce significantly the number of bacteria that is normally present on the skin. Before a procedure, personnel must first perform a surgical hand scrub and then don sterile gloves, sterile gown, and mask. The primary goal is to provide an environment for the patient that promotes healing, prevents infections, and minimizes the length of recovery time. Using the principles of sterile technique will help accomplish that goal. The principles are as follows: ■ All items used within a sterile field must be sterile. ■

A sterile barrier that has been permeated must be considered contaminated.

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The edges of a sterile container are considered contaminated once the package is opened.

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Gowns are considered sterile in front from shoulder to waist level, and the sleeves are considered sterile to 2 inches above the elbow.

■

Tables are sterile at table level only.

Chapter 3—Sterile Technique ■

Sterile persons and items touch only sterile areas; unsterile persons and items touch only unsterile areas.

■

Movement within or around a sterile field must not contaminate the field.

■

All items and areas of doubtful sterility are considered contaminated.

SURGICAL HAND SCRUB The surgical hand scrub has its own traditions and rituals dating back to the use of chlorinated lime by Semmelweis, who in 1846 recognized the role of contagions on doctors’ hands in the spread of puerperal fever, and the use of carbolic acid by Lister to soak his instruments and hands (Lister, 1867). The goal of the surgical hand scrub is to remove dirt and debris and to reduce bacterial flora. An ideal surgical hand scrub should provide the following antimicrobial effects: ■ Immediate reduction in the resident bacterial flora ■

Sustained effect to maintain a reduced bacterial count under surgical gloves

■

Cumulative effect with each additional application of the antiseptic

■

Persistent effect providing progressive reduction of bacteria with additional applications

The traditional 10-minute surgical scrub, using a stiff brush and harsh chemicals, does not meet the criteria for satisfactory antimicrobial action (an immediate reduction in microbial count that is sustained, cumulative, and persistent) and is associated with a number of difficulties and problems, chiefly a high incidence of irritation and dermatitis that can paradoxically result in an increased microbial population on the hands (Larson, 1986). Modifications have been made to the traditional surgical hand scrub to increase its beneficial effects and to decrease its harmful effects. The duration of the recommended scrub time has been decreased so that a 2-minute scrub time is now considered by some to be optimal (Wheelock, 1997). Some authors have recommended eliminating the scrub brush, to decrease abrasion of the hands (Gruendemann, 2001). New antiseptics, emollients, and humectants have been developed to minimize skin dryness and dermatitis resulting from the surgical hand scrub. New procedures and products for hand hygiene and the surgical hand scrub have been consolidated into a publication that was issued by the Centers for Disease Control and Prevention (CDC) in 2002. These guidelines are comprehensive, providing an analysis of the science of hand hygiene and specific recommendations for surgical hand antisepsis (CDC, 2002):

25

26

Chapter 3—Sterile Technique

SURGICAL HAND ANTISEPSIS 1. Remove rings, watches, and bracelets before beginning the “surgical hand scrub” (i.e., a process to remove or destroy transient microorganisms and reduce resident flora). 2. Remove debris from underneath fingernails using a nail cleaner under running water. 3. “Surgical hand antisepsis” (i.e., a process for removal or destruction of transient microorganisms) using either an antimicrobial soap or an alcohol-based hand rub with persistent activity is recommended before donning sterile gloves when performing surgical procedures. 4. When performing surgical hand antisepsis using an antimicrobial soap, scrub hands and forearms for the length of time recommended by the manufacturer, usually 2 to 6 minutes. Long scrub times (e.g., 10 minutes) are not necessary. 5. When using an alcohol-based surgical hand scrub product with persistent activity, follow the manufacturer’s instructions. Before applying the alcohol solution, prewash hands and forearms with a nonantimicrobial soap and dry hands and forearms completely. After application of the alcohol-based product as recommended, allow hands and forearms to dry thoroughly before donning sterile gloves.

Materials Utilized for Hand Scrub ■

Chlorhexidine gluconate or povidone-iodine solutions are rapid-acting, broad-spectrum antimicrobials that are effective against gram-positive and gram-negative microorganisms. Each is prepared in combination with a detergent to give a cleansing action along with the antimicrobial effect.

■

Sterile disposable scrub brushes impregnated with chlorhexidine gluconate, povidone-iodine, or other CDC-approved products (CDC, 2002).

Chapter 3—Sterile Technique

27

Procedures for the Surgical Scrub: Timed (Anatomic) and Counted Stroke Methods Note: Two methods of surgical scrubbing are typically used: the timed method (Fig. 3-1), which is illustrated here, and the counted stroke method. Both methods follow a prescribed anatomic pattern of scrubbing beginning with the fingernails, then moving on to the four surfaces of each finger, the palmar and dorsal surfaces of the hands and wrists, and extending up the arms to the elbows. The timed method requires a total of 5 minutes of scrub time. The counted stroke method requires a specific number of bristle strokes for the fingers, hands, and arms. The scrub includes 30 strokes for the fingernails and 20 strokes to each surface of the fingers, hands, wrists, and arms to the elbows.

4. Squeeze scrub brush under water to release soap from sponge. 5. With scrub brush perpendicular to fingers, begin to scrub all four sides of each finger with a back-and-forth motion. 6. Scrub dorsal and palmar surfaces of hand and wrist with a circular motion. 7. Starting at the wrist, scrub all four sides of the arm to the elbow. 8. Transfer scrub brush to the other hand and repeat steps 5 to 7. 9. Discard scrub brush and rinse hands and arms, starting with the fingertips and working toward the elbows. 10. Allow contaminated water to drip off the elbows by keeping hands above the waist

Materials Utilized to Prepare the Procedure Site Note: Preparation trays are commercially available and typically include the listed necessary items. • Disposable razors to remove hair from the procedure site FIGURE 3-1.

1. Organize supplies and adjust water to a comfortable temperature. 2. Wet hands and arms, prewash with soap from a dispenser, rinse. 3. Remove scrub brush from package and use nail cleaner to clean fingernails.

• Towels • Antiseptic soap: There are multiple antiseptic skin scrubs available. The most commonly used are iodine-based soaps and solutions. • Gauze sponges • Large clamp or ring forceps to hold the preparation sponge or gauze

28

Chapter 3—Sterile Technique

Procedure for Preparing the Operative Site 1. Scrub the skin with the antiseptic solution, beginning at the procedure site and working outward in a circular fashion toward the periphery of the field (Fig. 3-2). Make sure the area prepared is much wider than the procedure site. Note: The scrubbing action must be vigorous, including both mechanical and chemical cleansing of the skin. 2. On reaching the outer boundary, discard the first sponge and repeat the procedure until all prepared sponges are used.

Caution: Do not return to a previously prepared area with a contaminated sponge.

Materials Utilized for Draping a Patient and the Procedure Site Note: Draping the procedure site and the patient follows preparing the skin. • Drapes: typically green, blue, or gray to reduce glare and eye fatigue • Types of drapes: towels, sheets, split sheets, fenestrated sheets, stockinette, and plastic incision drapes Note: Each type of drape has a specific use; for example, fenestrated sheets have a window that exposes the procedure site, and stockinette is used to cover the extremities circumferentially. Drapes must be lint-free, antistatic, fluid resistant, abrasive-free, and made to fit contours.

FIGURE 3-2.

Procedure for Draping Note: Draping is the process of maintaining a sterile field around the procedure site by covering the surrounding areas and the patient with a barrier. 1. Hold the drapes high enough to avoid touching unsterile areas. 2. Always walk around the table to drape the opposite side.

Caution: Never reach over the patient. 3. Handle drapes as little as possible and avoid shaking out wrinkles (contaminants are present in the air). 4. When draping, make a cuff over the gloved hand to protect against touching an unsterile area, and place the folded edge toward the incision to provide a

Chapter 3—Sterile Technique uniform outline of the surgical site and to prevent instruments or sponges from falling between layers. Note: Any part of the drape below waist or table level is considered unsterile. Towel clips fastened through the drapes have contaminated points and should be removed only if necessary.

29

5. If a hole is found in a drape after it is placed, cover it with a second drape. 6. Drapes should not be adjusted after placement. If a drape is placed improperly, either discard it or cover it with another drape.

Procedure for Maintaining a Sterile Field Note: The sterile field includes the draped patient and any scrubbed personnel. 1. Someone outside the sterile field must hand items needed during the procedure into the sterile field. This is the reason a minimum of two individuals is required to do most procedures—one with unsterile hands to pass instruments and supplies into the sterile field, and one with gloved hands working within the sterile field. Note: Sterile supplies are uniformly packaged in such a way to allow an unsterile person to open and pass them safely, without contamination, into the sterile field. 2. Contamination of supplies or personnel within the sterile field must be addressed immediately. This includes changing gowns or gloves and removing from the

sterile field any instrument or supplies that have become contaminated. 3. Unsterile personnel must avoid contact with the sterile field by remaining at a safe distance (at least 12 inches away) and by always facing the field when passing to avoid accidental contact. 4. Every individual involved with the procedure must immediately call attention to any observed breaks, or suspected breaks, in sterile technique. 5. If the sterility of any item is in doubt, it must be considered contaminated, removed from the sterile field, and replaced with a sterile item. Caution: There is no compromise with sterility. An item is either sterile or unsterile.

Procedure for Wearing Surgical Masks, Caps, and Gowns Note: Because of the large number of potentially harmful microbes that reside in the respiratory tract, surgical masks are recommended at all times when there are open sterile items or sterile instruments present.

1. Fit the mask snugly over both the nose and the mouth and tie securely (Fig. 3-3). 2. When wearing a mask, keep conversation to a minimum to prevent moisture buildup. 3. Change surgical masks routinely between procedures or during a procedure if they become moist or wet. continued

30

Chapter 3—Sterile Technique

FIGURE 3-3.

Note: Surgical caps prevent unsterile material from the hair entering the sterile field. The standard unisex surgical cap is adequate for women and men with short hair, but a more voluminous cap is required for long hair. Both caps and masks generally are made of paper and are disposable. Note: For lengthy procedures, or when it is necessary to put the forearms into the sterile field, a sterile surgical gown is required (Figs. 3-4 and 3-5). Procedures for which gloves are sufficient include joint aspiration, suturing a minor laceration, and performing a lumbar puncture. A gown is required for repairing a large wound, for cardiac catheterization, or for any procedure that requires it by protocol. Only the front of the gown above the waist level and the lower portion of the sleeves are considered sterile. Even though the entire gown is sterile initially, brushing against an unsterile object with the back, sides, or lower portion of the gown is easy to do.

FIGURE 3-4.

FIGURE 3-5.

Chapter 3—Sterile Technique

SPECIAL CONSIDERATIONS Standard Precautions In 1987, the CDC developed universal precautions, later incorporated into standard precautions, which were designed to protect health care personnel from unknown exposures from the patient and environment. The CDC (1987) stated, “Since medical history and examination cannot identify all patients who are potentially infected with blood-borne pathogens, specific precautions should be used with all patients, thereby reducing the risk of possible exposure to its minimum.” Therefore, all procedures and patients should be considered to be potentially contaminated, and strict protocols should be followed to prevent exposure to blood and body fluids. The CDC advised that health care workers could reduce the risk of exposure and contamination by adhering to the following guidelines: 1. Use appropriate barrier protection to prevent skin and mucous membrane exposure when contact with blood and body fluids of any patient is anticipated. Gloves, masks, and protective eyewear or face shields should be worn during all surgical procedures and when handling soiled supplies or instruments during or after a procedure to prevent exposure of mucous membranes. 2. Wash hands and other skin surfaces immediately and thoroughly if contaminated with blood or other body fluids. Although both sterile and unsterile personnel wear gloves during a surgical procedure, hand washing after the removal of gloves should become a routine practice for all personnel working in a procedure room. 3. Take all necessary precautions to protect against injuries caused by needles, scalpels, and other sharp instruments or devices during procedures; when cleaning used instruments; and when handling sharp instruments after a procedure. Needles should never be recapped or bent after use. Suture needles and sharps should be contained in a puncture-resistant container and sealed for proper disposal according to recommended practices and established

31

protocols. Sharp instruments should be placed in a tray in such a way that their points are not exposed so that injury to persons working with the trays is avoided. During the procedure, care must be taken when handling suture needles to ensure that no one receives an injury by placing the needle on a needle holder and passing it with the point down. 4. Health care workers who have exudative lesions or weeping dermatitis should refrain from all direct patient care and from handling patient care equipment until the condition resolves. Individuals with minor breaks in the skin should restrict scrubbing activities until the breaks have healed. Sterile gloves should be worn if a skin lesion is present, and the lesion covered when working in a procedure room. The Occupational Safety and Health Administration (OSHA) has adopted these guidelines in its efforts to maintain a safe working environment. In addition, both OSHA and the CDC recommend that aspirated or drainage material never come into contact with health care providers. Thus, the use of an adequate suctioning system is important during procedures, with careful disposal protocols after the procedure is completed. For more information on standard precautions, see Chapter 2.

Disposal of Materials 1. Care should be taken to dispose of contaminated supplies and materials to avoid the transmission of infectious organisms to others. 2. Sharp objects should be disposed in appropriately marked containers. 3. Body fluids, human tissue, disposable gowns, gloves, caps, and drapes should be placed in containers marked with the appropriate biohazard warnings. 4. All receptacles containing biohazardous waste should be properly labeled and identified and processed according to institutional procedures.

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Chapter 3—Sterile Technique

REFERENCES Adams F: The Genuine Works of Hippocrates. New York, W. Wood, 1929. Centers for Disease Control and Prevention: Guideline for hand hygiene in health-care settings. MMWR Recomm Rep 51(RR-16):1-45, 2002. Centers for Disease Control and Prevention: Recommendations for prevention of HIV transmission in health-care settings. MMWR Morb Mortal Wkly Rep 36(suppl 2):1S-18S, 1987. Dubos R: Louis Pasteur: Free Lance of Science. Boston, Little, Brown, 1950. Godlee RJ: Lord Lister. London, Macmillan, 1917. Gruendemann BJ: Is it time for brushless scrubbing with an alcoholbased agent? AORN J 74:859-873, 2001. Larson E: Physiologic and microbiologic changes in skin related to frequent handwashing. Infect Control Hosp Epidemiol 7:59-63, 1986. Lister J: On a new method of treating compound fractures, abscess, etc. with observations on the conditions of suppuration. Lancet 1:326, 357, 507, 1867. Wheelock SM: Effect of surgical hand scrub time on subsequent bacterial growth. AORN J 65:1087-1098, 1997.

Chapter

4

Blood Pressure Measurement Randy Danielsen

PROCEDURE GOALS

AND

OBJECTIVES

Goal: To accurately measure the systemic arterial blood pressure in any patient in any setting. Objectives: The student will be able to …

•

Describe the indications, contraindications, and rationale for performing arterial blood pressure measurement.

•

Describe the essential anatomy and physiology associated with the performance of blood pressure measurement.

•

Identify the necessary materials and their proper use for performing blood pressure measurement.

•

Perform the proper steps and techniques for obtaining blood pressure measurement.

•

Describe the indications for performing orthostatic blood pressure assessment.

•

Perform the proper steps and techniques for obtaining orthostatic blood pressure measurement.

33

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Chapter 4—Blood Pressure Measurement

BACKGROUND AND HISTORY Various theories about circulation and blood pressure (BP) emerged about 400 BC. Hippocrates knew about arteries and veins, but he believed veins carried air. Six hundred years later, Galen demonstrated that both arteries and veins carried blood; however, he also thought that the heart was a warming machine for two separate types of blood. He was convinced that veins and arteries were not connected and that blood flowed both backward and forward from the heart. Subsequently Galen’s teachings remained unchallenged for over 1000 years (Stevens, 1978). It was William Harvey, in 1616, who disagreed with Galen by demonstrating one-way circulation of blood and theorized the existence of capillaries. Thirty years later, Marcello Malpighi was the first to view capillaries microscopically (Stevens, 1978). The first person to measure BP was Stephen Hales in 1733. An English physiologist, clergyman, and amateur scientist, Hales inserted a brass pipe into the carotid artery of a mare and then attached the pipe to a windpipe taken from a goose. The flexible goose windpipe was then attached to a 12-foot glass tube. Although the experiment had little practical application at the time, it did provide valuable information about BP (Wain, 1970). Although Ritter von Basch experimented with a device that could measure the BP of a human without breaking the skin, the prototype design of the sphygmomanometer was devised in 1896 by Scipione Riva-Rocci (Lyons, 1987). He introduced a method for indirect measurement of BP based on measuring the external pressure required to compress the brachial artery so that arterial pulsations could no longer be transmitted through the artery. The Riva-Rocci sphygmomanometer was described by Porter (1997) as “an inflatable band that was wrapped around the upper arm; air was pumped in until the pulse disappeared; it then was released from the band until the pulse reappeared, and the reading was taken.” In 1905, a Russian physician named Korotkoff first discovered the auscultatory sounds that are heard while measuring BP. While the artery is occluded during BP measurement, transmitted pulse waves can no longer be heard distal to the point of occlusion. As the pressure in the bladder is reduced by opening a valve on the inflation bulb, pulsatile blood flow reappears through the generally compressed artery, producing repetitive sounds generated by the pulsatile flow. The sounds, named after Korotkoff, change in quality and intensity. The five phases of these changes are characterized in Table 4-1. Around the turn of the 20th century, BP became an accepted clinical measurement. As data increased, physicians and other clinicians were able to establish normal BP ranges and identify abnormalities. René Laënnec is credited with the invention of the stethoscope in 1816, which became a convenience for physicians who preferred not to place their ears directly on the chest wall of a patient. In 1905, Korotkoff tried using the stethoscope to monitor the pulse while the sphygmomanometer was inflated. He discovered a more accurate BP reading and that the pulse disappeared as the cuff pressure decreased at a point in consonance with the expanding of

Chapter 4—Blood Pressure Measurement Table 4.1

Korotkoff Sounds*

From Perloff D, Grimm C, Flack J, et al: Human blood pressure determination by sphygmomanometry. Circulation 88:2461, 1993.

the heart. Subsequently, the term Korotkoff sounds came to be used (Lyons, 1987). According to Grim and Grim (2000): Indirect BP measurement is one of the most frequently performed health care procedures. Because BP measurement is a simple procedure, it is taken for granted that all graduates from medical training programs have the ability to record accurate, precise, and reliable BP readings. However, research since the 1960s has shown this assumption to be false. Most health professionals do not measure BP in a manner known to be accurate and reliable. The authors describe two factors that contribute to inaccurate BP measurement: (1) lack of depth in the instruction of basic skills in professional education; and (2) relying on nonmercury devices. Subsequently, every clinician who takes BP measurements should know and understand the principles and steps needed to obtain accurate indirect auscultatory BP measurement. The measurement taken is an important tool in screening and diagnosis, which is why it is considered one of the patient’s “vital signs.” For the accurate indirect measurement of BP, the American Heart Association (AHA) recommends that the cuff size be based solely on the limb circumference. Manning, Kuchirka, and Kaminski studied prevailing cuffing habits, compared them with AHA guidelines, and reported their findings in Circulation in 1983. They found that “miscuffing” occurred in 65 (32%) of 200 BP determinations in 167 unselected adult outpatients, including 61 (72%) of 85 readings taken on “nonstandard-size” arms. Undercuffing large arms was the most frequent error, accounting for 84% of the miscuffings. They concluded that undercuffing elevates the BP readings by an average of 8.5 mm Hg systolic and 4.6 mm Hg diastolic. It is critical, therefore, that the clinician choose the appropriate size cuff based on the circumference of a patient’s bare upper arm. The bladder (inside the cuff) length should encircle 80% and the width should cover 33% to 50% of an adult’s upper arm. For a child younger than 13 years of age, the bladder should encircle 100% of the child’s

35

36

Chapter 4—Blood Pressure Measurement upper arm. A cuff that is too narrow or too large for an arm may result in an incorrect BP reading. Cuffs that are generally available usually have been classified by the width of the bladder rather than by the length and are labeled newborn, infant, child, small adult, adult, large adult, and thigh. Over- and underestimation of BP by using an inappropriate cuff size has been well documented in the literature. Health care settings should have easy access to small, standard, and large cuffs (Graves, 2001).

INDICATIONS As one of the vital signs, peripheral BP measurement is an indirect method of determining cardiovascular function. Its use is indicated for evaluation of both healthy and unhealthy patients to assess cardiac status. BP measurement is a part of every complete physical or screening examination and is performed to screen for hypertension or hypotension.

CONTRAINDICATIONS There are no absolute contraindications to measuring BP. Relative contraindications include physical defects and therapeutic interventions, such as indwelling intravenous catheters and renal dialysis shunts.

POTENTIAL COMPLICATIONS Complications from measurement of BP occur as a result of improper training of the individual performing the assessment. Overinflation or prolonged time of inflation may lead to tissue or vascular damage at the measurement site. Lack of proper care of equipment or flawed equipment may give an inaccurate reading.

REVIEW OF ESSENTIAL ANATOMY AND PHYSIOLOGY In most clinical settings, BP is measured by the indirect technique of using a sphygmomanometer placed over the brachial artery of the upper extremity. The brachial artery is a continuation of the axillary artery, which lies medial to the humerus proximally and gradually moves anterior to the humerus as it nears the antecubital crease (Fig. 4-1). Placement of the bladder and cuff of the sphygmomanometer circumferentially over the brachial artery allows inflation of the cuff to create adequate pressure so that the artery is fully occluded when the pressure exceeds the systolic pressure within the brachial artery.

Chapter 4—Blood Pressure Measurement

Humerus

Brachial artery

Antecubital crease

Radial artery

Ulnar artery

FIGURE 4-1. Location of the brachial artery.

Indirect measurement of the BP involves the auscultatory detection of the initial presence and disappearance of changes and the disappearance of Korotkoff sounds, which are audible with the aid of a stethoscope placed over the brachial artery distal to the BP cuff near the antecubital crease. Korotkoff sounds are low-pitched sounds (best heard with the stethoscope bell) that originate from the turbulence created by the partial occlusion of the artery with the inflated BP cuff. As long as the pressure within the cuff is so little that it does not produce even partial occlusion (or intermittent occlusion), no sound is produced when auscultating over the brachial artery distal to the cuff. When the cuff pressure becomes great enough to occlude the artery during at least some portion of the arterial pressure cycle, a sound becomes audible over the brachial artery distal to the cuff. This sound is audible with a stethoscope and correlates with each arterial pulsation. There are five phases of Korotkoff sounds used in determining systolic and diastolic BP (see Table 4-1). Phase I occurs as the occluding pressure of the cuff falls to a point that is the same as the peak systolic pressure within the brachial artery (Fig. 4-2). The tapping sound that is produced is clear and generally increases in intensity as the occluding pressure continues to decrease. Phase II occurs at a point approximately 10 to 15 mm Hg lower than at the onset of phase I, and the sounds become softer and longer with a quality of intermittent murmur. Phase III occurs when the occluding pressure of the cuff falls to a point that allows for large amounts of blood to cross the

37

38

Chapter 4—Blood Pressure Measurement Brachial artery occluded by cuff, no blood flow 160

Artery intermittently compressed, blood spurts into artery 160

120

120

120

80

80

80

40

40

40

I Auscultatory sound

Silence

FIGURE 4-2.

Cuff deflated, artery flows free 160

IV Clear tapping

Abrupt muffling

V Silence

Phase 1 of Korotkoff sounds.

partially occluded brachial artery. The phase III sounds are again crisper and louder than phase II sounds. Phase IV occurs when there is an abrupt muffling and decrease in the intensity of the sounds. This occurs as the pressure is close to that of the diastolic pressure of the brachial artery. Phase V occurs when the blood vessel is no longer occluded by the pressure in the cuff. At this point, the tapping sound disappears completely.

PATIENT PREPARATION Ideally, the environment should be relaxed and peaceful. BP levels may be affected by emotions, physical activity, or the environment. Subsequently, the examiner should minimize any and all disturbances that may affect the reading. The procedure should be explained to the patient. The patient is asked to be seated or to lie down with the back supported, making sure that the bare arm is supported horizontally at the level of the heart. According to Mourad and Carney (2004): Choosing the dependent arm is a behavior likely to lead to the overdiagnosis of hypertension and inappropriate treatment of hypertension because the dependent arm falsely elevates both systolic and diastolic blood pressure. These results should encourage national and international organizations to reaffirm the importance of the horizontal arm in the measurement of blood pressure. The clinician should avoid an arm that appears injured or has a fistula or an IV or arterial line. If the patient has undergone breast or axilla surgery, avoid the arm on the same side. It is important to note that rolling up the sleeves

Chapter 4—Blood Pressure Measurement Cloth cuff

Inflatable rubber bladder

Mercury manometer

Stethoscope

Insufflation bulb with pressure control valve

Aneroid manometer

FIGURE 4-3.

Instruments used for recording blood pressure.

has the potential of compressing the brachial artery and may have an even greater effect on the BP than if the shirt is left under the manometer’s cuff (Lieb, 2004) The patient should avoid smoking or ingesting caffeine for 30 minutes before the BP is recorded.

Materials Utilized for Blood Pressure Measurement ■

Stethoscope

■

Calibrated sphygmomanometer (a mercury, aneroid, or hybrid sphygmomanometer with a calibrated scale for measuring pressure; inflatable rubber bladders; tubes; and valves). There continues to be environmental concern over the use of mercury sphygmomanometers because of the hazards of mercury spills and potential exposure (see “Note”). As a result, more automated devices are being used (Valler-Jones, 2005). One of the factors affecting the accuracy of BP measurement is the equipment used. Defects or inaccuracy of aneroid sphygmanometers may be a source of error in BP measurement.

■

Recording instruments (Fig. 4-3)

39

40

Chapter 4—Blood Pressure Measurement ■

Appropriate size cuff: A cuff that has an antimicrobial agent to help prevent bacterial growth is recommended. It has been reported that BP cuffs can carry significant bacterial colonization and actually can be a source of transmission of infection (Base-Smith, 1996).

Note: Modern sphygmomanometers are less likely to spill mercury if dropped. If a spill occurs, however, mercury is fairly simple to clean up unless it is spilled within heated devices or is trapped in upholstery, carpeting, or other surfaces. Unfortunately, mercury in the organic form is extremely toxic via skin contact, inhalation, and ingestion and may require the calling of a hazardous materials team. If mercury manometers are used, a mercury spill kit is recommended.

Procedure for Indirect Blood Pressure Measurement 1. Check to see that the mercury level of the sphygmomanometer is at 0 or, if an aneroid device is used, that the needle rests within the calibration window. 2. Palpate the brachial artery and place the cuff so that the midline of the bladder is over the arterial pulsation. Care should be taken that the cuff is placed at approximately the horizontal level of the heart. 3. Wrap and secure the cuff snugly around the patient’s bare upper arm. The lower edge of the cuff should be 1 inch (approximately 2 cm) above the antecubital crease, the point at which the bell of the stethoscope is to be placed (Fig. 4-4). As noted earlier, avoid rolling up the sleeve in such a manner that it may form a tight tourniquet around the upper arm. 4. Place the manometer so that the center of the mercury column or aneroid dial is at eye level and clearly visible to the examiner. Make sure that the tubing from the cuff is unobstructed. 5. Inflate the cuff rapidly to 70 mm Hg and increase by increments of 10 mm Hg while palpating the radial pulse. Note the

Brachial artery

Blood pressure cuff and bladder

1 inch

Radial artery

Antecubital crease

Ulnar artery

FIGURE 4-4.

level of pressure at which the pulse disappears and subsequently reappears during deflation. This procedure, the palpatory method, provides the necessary preliminary approximation of

Chapter 4—Blood Pressure Measurement the systolic pressure to ensure an adequate level of inflation when the actual, auscultatory measurement is accomplished. The palpatory method is particularly useful to avoid underinflation of the cuff in patients with an auscultatory gap and overinflation in those with very low BP. The auscultatory gap occurs at a point between the highest systolic reading and the diastolic reading. The Korotkoff sounds may become absent between the peak systolic measurement and diastole, resulting in underestimation of the peak systolic BP if the cuff is not initially inflated to a high enough pressure.

41

FIGURE 4-5.

6. Place the earpieces of the stethoscope into your ear canals, angled forward to fit snugly. 7. Switch the stethoscope head to the lowfrequency position (bell). 8. Place the bell of the stethoscope over the brachial artery pulsation just above and medial to the antecubital crease but below the lower edge of the cuff (Fig. 4-5). Hold it firmly in place, making sure the bell makes contact with the skin around the entire circumference. Excessive pressure will result in stretching the underlying skin, causing the bell to function as a diaphragm. This may result in the loss of low-frequency sounds. 9. Inflate the bladder rapidly and steadily to a pressure 20 to 30 mm Hg above the level previously determined by palpation. Partially unscrew the valve and deflate the bladder at 2 mm per second while listening for the appearance of Korotkoff sounds.

10. As the pressure in the bladder falls, note the level of the pressure on the manometer at the first appearance of repetitive sounds, the continuation of the sounds, and when the sounds disappear. During the period of the Korotkoff sounds (see Table 4-1), the rate of deflation should be less than 2 mm per beat, thereby compensating for both rapid and slow heart rates. 11. Record the systolic and diastolic pressure immediately, rounded off upward to the nearest 2 mm Hg. The name of the patient, the date and time of measurement, the arm or site at which the measurement was taken, the cuff size, and the patient’s position while taking the measurement should be noted. 12. Neither the patient nor the clinician should talk during the measurement.

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Chapter 4—Blood Pressure Measurement

SPECIAL CONSIDERATIONS THE APPREHENSIVE PATIENT COAT” HYPERTENSION

OR

“WHITE

Ambulatory blood pressure measurement (ABPM) is increasingly being used in clinical practice (O’Brien, 2003). ABPMs correlate better than clinical measurements on patients with end-organ injury (Verdecchia, 2000). Twentyfour-hour ABPM is the most efficient means for assessing white coat hypertension (WCH), particularly in the absence of end-organ disease. WCH has been defined as clinical BP greater than 140 mm Hg systolic and 90 mm Hg diastolic (Al-Hermi, 2004). Ambulatory measurements are also valuable in assessing patients with apparent drug resistance, low BP symptoms, and in patients taking antihypertensive medications. There is now wider acceptance of BP readings taken by patients in their homes. Patients should be encouraged to monitor their BP at home with validated devices followed by appropriate recording and reporting to their clinician.

THE OBESE

OR

LARGE ARM

It is well known that BP measurement with a standard 12- to 13-inch (27- to 34-cm) wide cuff is inappropriate for large or obese arms. If the arm circumference of the patient exceeds 13 inches (34 cm), use a thigh cuff 17 to 20 inches (18 cm) wide on the patient’s upper arm. Table 4-2 gives acceptable bladder dimensions for adult arms of different sizes. In patients with extremely large arms, place the cuff on the patient’s forearm and listen over the radial artery. Occasionally, it may be necessary to determine the BP in the leg; this may be required to rule out coarctation of the aorta or if an upper extremity BP determination is contraindicated. To do this, use a wide, long thigh cuff

Table 4.2

Acceptable Bladder Dimensions for Arms of Different

Sizes*

From http://www.americanheart.org/presenter.jhtml?identifier=3000861; accessed May 6, 2006.

Chapter 4—Blood Pressure Measurement with a bladder size of 45 to 52 cm and apply it to the mid-thigh. Center the bladder over the posterior surface, wrap it securely, and listen over the popliteal artery (Perloff, 1993). According to Pickering and colleagues (2005), “wrist monitors may be useful in very obese patients if the monitor is held at heart level. Finger monitors are not recommended.” Block and Schulte (1996) discussed ankle BP measurements and found that mean BP readings obtained at the arm and at the ankle were statistically equivalent and concluded that ankle cuff placement provided a reliable alternative to the placement of the cuff on the arm.

INFANTS

AND

CHILDREN

Measuring BP in infants and children presents special problems to the clinician. The same measuring techniques are used as in adults. As mentioned earlier, pediatric cuff sizes are available to ensure that the bladder completely encircles the upper arm. Various techniques can enforce patient compliance—using relaxation techniques for the child, having the mother inflate the BP cuff, and/or demonstrating BP measurement on a stuffed animal.

ELDERLY PATIENTS In elderly patients, who may have significant atherosclerosis, it is likely that the systolic pressure is overestimated by the indirect method of BP measurement. BP tends to be more labile in elderly patients, so it is important to obtain several baseline measurements before making any diagnostic or therapeutic decisions (Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure, 2003). ABPM is very useful in this age group.

ASSESSMENT PRESSURE

OF

ORTHOSTATIC BLOOD

The measurement of orthostatic BP is an essential clinical tool for the assessment and management of patients suffering from many common medical disorders. The most common causes are volume depletion and autonomic dysfunction. According to Carlson (1999), orthostatic hypotension, which is a decline in BP when standing erect, is the “result of an impaired hemodynamic response to an upright posture or a depletion of intravascular volume. The measurement of orthostatic blood pressure can be done at the bedside and is therefore easily applied to several clinical disorders.” Orthostatic hypotension is detected in 10% to 20% of community-dwelling older individuals (Mader, 1987). This condition is frequently asymptomatic, but disabling symptoms of light-headedness, weakness, unsteadiness, blurred vision, and syncope may occur.

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Chapter 4—Blood Pressure Measurement The American Academy of Neurology’s consensus statement (1996) defines orthostatic hypotension as a “reduction of systolic blood pressure of at least 20 mm Hg or diastolic blood pressure of at least 10 mm Hg within 3 minutes of standing.” Many clinicians use a combination of a decrease in BP combined with an increase in heart rate to determine the presence of orthostatic hypotension. Performing these orthostatic measurements requires adequate techniques in BP measurement, appropriate positioning of the patient, and proper timing of the measurements.

Materials Utilized for Measuring Orthostatic Blood Pressure This technique requires the same equipment as previously mentioned for measuring BP.

Procedure for Measuring Orthostatic Blood Pressure 1. Ask the patient about his or her ability to stand. 2. Make sure the cuffed arm is positioned so that the brachial artery is held at the level of the heart. 3. After 5 to 10 minutes of supine rest, take a baseline BP and pulse. 4. Have the patient sit on the side of the bed with feet dangling for 2 to 3 minutes, then take BP and pulse.

6. Repeat the measurements again 1 to 3 minutes after continued standing. When recording the measurements, include the position when you took the readings and any signs or symptoms developed with postural changes. Throughout the procedure assess the patient for dizziness, light-headedness, pallor, sweating, or syncope. If any of these occur, return the patient to a supine position.

5. Repeat the measurements immediately upon having the patient stand.

FOLLOW-UP CARE AND INSTRUCTIONS The results of the BP measurements dictate the follow-up actions and patient instructions. Long-term observations have been made on the contributions of high BP to illness and death. It is important to note that the classification of BP has changed over the years. In 2003, the seventh report of the Joint National Committee (JNC-VII) on prevention, detection, evaluation, and treatment recommended the classification found in Table 4-3.

Chapter 4—Blood Pressure Measurement Classification of Blood Pressure (BP) for Adults 18 Years and Older

Table 4.3

CLASSIFICATION Normal Prehypertension Stage 1 hypertension Stage 2 hypertension

SYSTOLIC BP (mm Hg) 106/mm3), consumption of O2 may be great because of the breakdown of the excess cells. This is accompanied by a release of CO2, causing a pseudoacidosis. A delay in analysis or improper chilling enhances this effect. The PCO2 rises approximately 3 to 10 mm Hg per hour in an un-iced specimen, but it is stable for approximately 1 to 2 hours in a properly iced specimen. • Excess heparin in the syringe causes a decrease in pH. This is due to the low pH of heparin and the dilutional effects on the bicarbonate present in the sample.

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Chapter 8—Arterial Puncture

FOLLOW-UP CARE AND INSTRUCTIONS ■

Patients who have undergone this procedure must be monitored to ensure that hemostasis has been achieved.

■

Advise the patient that a small amount of tenderness and ecchymosis may result from the procedure.

■

Advise the patient to seek evaluation if he or she experiences increasing pain, redness, or coolness of the extremity distal to the arterial puncture site.

■

Patients should avoid rigorous activity for at least 24 hours.

REFERENCE McCall RT, Tankersley CM: Phlebotomy Essentials, 2nd ed. Philadelphia, JB Lippincott, 1998.

BIBLIOGRAPHY Bhardwaj D, Norris A, Won DT: Is skin puncture beneficial prior to arterial catheter insertion? Can J Anaesth 46:129-132, 1999. Chestnutt MS, Dewar TN, Locksley RM, Chestnutt M: Office and Bedside Procedures. New York, McGraw-Hill, 1996, pp 116-127. Fowler GC: Arterial puncture. In Pfenninger JL, Fowler GC (eds): Procedures for Primary Care Physicians. St. Louis, Mosby–Year Book, 2003, Ch 79. Giner J, Casan P, Belda J, et al: Pain during arterial puncture. Chest 110:1443-1445, 1996. Gomella LG: Clinician’s Pocket Reference, 10th ed. New York, McGraw-Hill, 2004, pp 249-251. Lightowler JV, Elliot MW: Local anesthetic infiltration prior to arterial puncture for blood gas analysis: A survey of current practice and a randomised double blind placebo controlled trial. J R Coll Phys Lond 31:645-646, 1997. Macklis RM, Mendelsohn ME, Mudge GH: Introduction to Clinical Medicine, 3rd ed. Philadelphia, Lippincott-Raven, 1994, pp 123-129. Marini JJ, Wheeler AP: Critical Care Medicine: The Essentials. Philadelphia, Lippincott Williams & Wilkins, 1997, pp 105-107. Okeson GC, Wulbrecht PH: The safety of brachial artery puncture for arterial blood sampling. Chest 114:748-751, 1998.

Chapter

9

Injections Conrad J. Rios This chapter was adapted from the 1st edition chapter written by Robert J. McNellis, MPH, PA-C. Mr. McNellis is the Director of Clinical Affairs and Education for the American Academy of Physician Assistants in Alexandria, Virginia.

PROCEDURE GOALS

AND

OBJECTIVES

Goal: To perform an injection successfully while observing standard precautions and with the minimal degree of risk to the patient. Objectives: The student will be able to …

•

Describe the indications, contraindications, and rationale for administering an injection.

•

Identify and describe common complications associated with administering injections.

•

Describe the essential anatomy and physiology associated with performing an injection.

•

Identify the materials necessary for performing an injection and their proper use.

•

Identify the important aspects of patient care after an injection.

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BACKGROUND AND HISTORY This chapter covers the most common procedures for parenteral administration of medications. Although parenteral means any route other than enteral (gastrointestinal), it ordinarily refers to methods of giving drugs by injection. The most common routes of parenteral medication administration are intradermal, subcutaneous, intramuscular, and intravenous. Intravenous procedures are covered in Chapter 7. Injections are part of the armamentarium of most medical disciplines. In addition to this common ground, each specialty has its own particular applications (Brokensha, 1999). The first experiments with intravenous injections were carried out in 1642 by a gentleman’s hunting servant in eastern Germany. Similar experiments were performed in 1656 by Christopher Wren (an astronomer, mathematician, and architect in Oxford, England) and by a group of scientists associated with the physicist Robert Boyle. These experiments were prompted by new knowledge about blood circulation provided by William Harvey in 1628. The first books on the applications of intravenous infusions in humans were published in 1664 and 1667. Bladders of animals or enema syringes were used as instruments. Because of lethal accidents, the infusions soon fell out of favor (Feldmann, 2000). Reinier de Graaf has been credited with the invention of the injection syringe in the late 1660s. De Graaf studied under anatomist Johannes van Horne at the newly established University of Leyden in Holland. As a young student, De Graaf helped Van Horne prepare anatomic specimens, and he used the injection syringe to introduce liquids and wax into the prepared blood vessels as a coloring and preservation medium. In 1853, Charles Pravaz, a French surgeon in Lyon, invented a small syringe, the piston of which could be driven by a screw, allowing exact doses. A sharp needle with a pointed trocar could be introduced into a vessel, making dissection unnecessary. Pravaz used his syringe for obliteration of arterial aneurysms by injection of ferric sesquichlorate. Pravaz’s syringe initiated the invention of a great number of various calibrated syringes made of glass or metal combined with glass. The calibrated syringes were commonly used in the treatment of syphilis by mercurialization. Also in 1853, in a paper entitled “A New Method of Treating Neuralgia by Direct Application of Opioids to the Painful Point,” Alexander Wood introduced his hollow needle in London, England. Within 5 years, injections of morphine had become enormously popular; thriving practices developed in response to what was seen as a potent, benign, and beneficial treatment. Patients were treated with hundreds of injections. Their doctors seemed blissfully unaware of the systemic effects of the drug they were injecting and the nature of the demand for the new treatment. Charles Hunter, another English physician, was discouraged from using the new technique when his first two patients developed local abscesses. In 1858, he discovered that patients gained just as much benefit from injections distant from the painful site. Hunter coined the term hypodermic and claimed

Chapter 9—Injections that his treatment was superior to that of Wood. Physicians debated the merits of the two physicians’ claims and decided in Hunter’s favor. During the debate, physicians continued with both treatments, apparently blind to the addiction underlying the huge and increasingly lucrative demand (Howard-Jones, 1971). Since the 19th century, there have been great advances in understanding the mechanisms of action of parenteral medications and improvements in the technology of injections. However, the basic principles remain the same. Today, injections can be given in any space or potential space; they can be administered hypodermically under direct vision or guided by ultrasonography or radiography, as well as through the use of endoscopic techniques. The widespread use of needleless (jet) injection systems is just on the horizon. Delivery systems that are less invasive, such as nasal sprays, transdermal patches, and continuous infusion devices, may make injections less and less common.

INDICATIONS Indications include an illness or injury that requires parenteral medication to improve, treat, or maintain the patient’s condition, as well as administration of vaccines for disease prevention. Caution: As with other medical therapies, the patient has the right to refuse an invasive procedure such as an injection.

CONTRAINDICATIONS Potential contraindications to injections include the following conditions: ■ Allergy to the intended medication ■

Lack of a suitable site for injection

■

Coagulopathy

■

Occlusive peripheral vascular disease

■

Shock

■

Impairment of peripheral absorption

POTENTIAL COMPLICATIONS ■

Anaphylactic or toxic reaction to the medication: Treatment is supportive for anaphylaxis and may vary depending on the severity of the reaction. Medication to reverse the toxic effect of the drug should be readily available. Risk of anaphylaxis can be minimized by asking the patient about allergies or checking medical alert bracelets before injection.

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Chapter 9—Injections ■

Medication error: Errors often can be avoided by using the “five rights” as guidelines for the administration of medication. These guidelines ensure that the right drug is given to the right patient in the right dose by the right route at the right time: ■ Right drug: The medication label should be checked three times: when the drug is taken from storage, when the amount of drug is removed, and when the container is returned to storage. ■

Right patient: Always check the patient’s identification bracelet or ask the patient to state his or her name.

■

Right dose: Errors in dose are minimized when the unit system is used and a pharmacist prepares drugs. If a drug dose for an infant or child must be calculated, have a second person check the arithmetic, because even a small error can lead to a serious overdose. It is good practice to have a second person double check doses of heparin, insulin, and epinephrine.

■

Right route: Only give injections of substances prepared for parenteral use; it should say “injectable” on the label. Avoid giving an inadvertent intravenous injection by drawing back before pushing the drug.

■

Right time: It is important to know why a drug is ordered for a certain time. Be sure to document when drugs were given.

■

The practitioner is responsible for the medications that are administered. Administer only the drugs prepared personally or those that were prepared by the pharmacist, unless there is an emergency situation.

■

Infection or abscess at the site: Infection typically occurs as the result of improper aseptic technique. Sterile abscesses can occur after injecting concentrated or irritating solutions. Rotating injection sites can minimize this complication. Injections should be avoided at sites that are inflamed, edematous, or irritated and at sites with moles, birthmarks, scar tissue, or other lesions.

■

Lipodystrophy or atrophy of subcutaneous fat, which is caused by repeated injections at the same site: Rotating injection sites can minimize this complication.

■

Injection pain: Minimize the use of irritating solutions given subcutaneously to reduce pain. Techniques to reduce the pain of intramuscular injections include having the patient relax the muscle, avoiding extrasensitive areas, waiting until the antiseptic is dry before injecting the medication, using a new needle for injection, inserting and withdrawing the needle rapidly, massaging the muscle after injection to distribute the medication better and increase its absorption, and using ice or topical spray to numb the area before injection.

Chapter 9—Injections

FIGURE 9-1.

Sites for subcutaneous injection.

REVIEW OF ESSENTIAL ANATOMY AND PHYSIOLOGY Intradermal injections are given in the outer layers of the skin. There is little systemic absorption of intradermally injected agents, so this type of injection is given primarily to produce a local effect. The ventral forearm is the most commonly used site because of its easy accessibility and lack of hair. In extensive allergy testing, the outer aspect of the upper arms and the area of the back between the scapulae are used. Subcutaneous injections are given into the adipose tissue beneath the skin. The most common sites are the outer aspects of the upper arm, anterior thigh, loose tissue of the lower abdomen, upper buttocks, and upper back (Fig. 9-1). Intramuscular injections deposit medication deep into muscle tissue, where it can be readily absorbed. The rate of drug absorption is faster than with the subcutaneous route but slower than with the intravenous route. Intramuscular sites (Fig. 9-2) include the following: ■ Deltoid muscle: The deltoid muscle is located on the lateral side of the humerus. Place four fingers across the deltoid muscle, with the top finger along the acromion process. The injection site is two to three fingerbreadths below the acromion process (Fig. 9-3). Injecting lower or more posterior in the muscle can result in injury to the radial and ulnar nerves or brachial artery. ■

Dorsogluteal (gluteus medius): Locate the posterior superior iliac spine and the greater trochanter of the femur. Draw an imaginary line between the two landmarks. The injection site is above and lateral to the line. A less accurate method is dividing the buttocks into quadrants. The

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Deltoid

Dorsogluteal

Ventrogluteal Vastus lateralis

FIGURE 9-2.

Sites for intramuscular injection.

Acromion process Scapula

Injection area

Deltoid

Biceps Triceps

FIGURE 9-3.

Deltoid muscle.

Chapter 9—Injections Posterior superior iliac spine

Iliac crest

Gluteus medius

Gluteus minimus

Greater trochanter of femur Gluteus maximus

FIGURE 9-4. Inject above and lateral to dotted line.

vertical dividing line extends from the gluteal fold up to the iliac crest. The injecting horizontal line extends from the medial fold to the lateral aspect of the buttock. The injection site is the upper outer quadrant, about 2 to 3 inches below the iliac crest. The risk of injury to the sciatic nerve can be great at this site; injury can cause paralysis of the affected leg (Fig. 9-4). ■

Ventrogluteal (gluteus medius and gluteus minimus): Place the heel of your hand over the greater trochanter. Point the thumb toward the groin and fingers toward the head. Place the index finger over the anterosuperior iliac spine and extend the middle finger along the iliac crest. The index finger and middle finger form a V. Inject into the center of the V. The muscles of this site are deep and away from major nerves and blood vessels (Fig. 9-5).

■

Vastus lateralis muscle: This muscle is located at the anterolateral aspect of the thigh and extends from a handbreadth above the knee to a handbreadth below the greater trochanter of the femur. The middle third of the muscle is the best site for injection. This site is a well-developed muscle that lacks major nerves and blood vessels. The branches of the lateral femoral cutaneous nerve are located superficially, and a few cases of damage to these branches have been reported. It is the preferred site for infants, children, and adults (Fig. 9-6).

Parenteral medication administration provides longer action and avoids the first-pass metabolic effects of the liver. Each route of administration has advantages and disadvantages:

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Anterior superior iliac spine

Injection site

Greater trochanter of femur

Iliac crest

Gluteus medius

Sacrum

Gluteus maximus

FIGURE 9-5.

Ventrogluteal site.

Gluteus maximus Rectus femoris

Biceps femoris

Vastus lateralis

Injection site

Knee

FIGURE 9-6.

Vastus lateral site.

■

Intradermal injections have slow absorption, which is an advantage when testing for allergies.

■

The disadvantages of intradermal injections are that only small amounts of drug may be administered and they require an aseptic technique.

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Subcutaneous injections have the advantage of faster onset of drug action than the oral route.

■

Disadvantages of subcutaneous injections include the need for aseptic technique, their greater expense when compared with oral medication, the small volume that can be administered, and the potential to produce anxiety; some drugs can irritate tissues and cause pain.

Chapter 9—Injections ■

Intramuscular injections minimize pain from irritating drugs, have larger volumes of drug that can be administered compared with the subcutaneous route, and provide rapidly absorbed medication.

■

Disadvantages of intramuscular injections include the need for aseptic technique, the possibility of blood vessel and nerve damage, and the potential to produce anxiety.

Standard Precautions Every practitioner should use standard precautions at all times when interacting with patients, especially when performing procedures. Determining the level of precaution necessary requires the

101

practitioner to exercise clinical judgment based on the patient’s history and the potential for exposure to body fluids or aerosol-borne pathogens (for further discussion, see Chapter 2).

PATIENT PREPARATION ■

Explain to the patient why it is necessary to administer the injection.

■

Obtain verbal consent to give an injection.

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Ask the patient if he or she is allergic to any medications and the type of reaction that occurs.

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Inform the patient of the benefits and risks in understandable language.

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Inform the patient which site will be used for administering the injection.

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Tell the patient that there will be a sting or pricking sensation felt when the needle is inserted.

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Warn the patient of potential side effects, and advise the patient of signs and symptoms to watch for.

■

Ask again about allergies.

Materials Utilized for Administering an Injection ■

Appropriate medication

■

Syringe and needle

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Materials for cleansing the skin: alcohol pad, most commonly saturated with 70% isopropyl alcohol

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Sterile or unsterile gloves

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Needle disposal box

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Bandage strips and gauze pads

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Chapter 9—Injections Note: Medication comes in many forms: ■ Ampule containing a single drug dose ■

Vial containing single or multiple drug doses

■

Vial containing powder to which a sterile diluent or solvent must be added with some drugs

■

Prefilled cartridge package

■

Syringe

Note: Syringes range in size from a capacity of 1 mL to 50 mL, but syringes larger than 5 mL are rarely used for injections. A 2- or 3-mL syringe is adequate for most subcutaneous and intramuscular injections. Most institutions use plastic syringes, although some medications in prefilled cartridges require cartridge syringes (e.g., Tubex). Insulin syringes have a capacity of 1 mL and are calibrated in units. There is a syringe designed for use with each strength of insulin. For example, a syringe marked U100 is coded to match the label of a vial of insulin that contains 100 units/mL. Tuberculin syringes also have a capacity of 1 mL, but they are long, slender, and calibrated in 0.01-mL units. This fine calibration makes it possible to administer very small amounts of potent drugs, such as those used for intradermal skin testing. ■

Barrel of the syringe, handle of the plunger, and hub of the needle

Note: These parts must, out of necessity, be handled during the preparation and administration of an injection, but the inside and tip of the barrel and the shaft of the plunger must be kept sterile, as must the entire length of the needle (Fig. 9-7). ■

Needle

Note: Needles that are commonly used for injections vary in length from 1⁄2 to 11⁄2 inches; they vary in diameter from 14 to 26 gauge (the larger the gauge, the smaller the diameter). A common size for a subcutaneous injection is 25 gauge, 5⁄8 inch; the needle for an intramuscular injection is larger and longer: 18 to 22 gauge, 11⁄2 inches. Typically, needles for intradermal injections are 26 or 27 gauge and 1⁄2 to 5⁄8 inch long. Needles are packaged individually to permit greater flexibility in selecting the right needle for a specific patient. A syringe and needle may be packaged Barrel

Plunger

Hub

Tip

FIGURE 9-7.

Parts of a syringe and needle.

Bevel

Needle

Chapter 9—Injections

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together if the size of the needle is relatively standard, such as an insulin or tuberculin syringe and needle. Note: The length of the needle is determined by the size and weight of the patient and whether the drug will be injected subcutaneously or intramuscularly. The gauge depends on the viscosity of the fluid to be injected. A thin, watery, nonsticky solution can be injected easily through a fine-gauge needle (25 or 26), but a thicker, sticky solution requires a larger gauge needle (20 to 22). Note: Many institutions are beginning to move toward needleless or safety needle systems for injections. In these systems, medication can often be drawn through vials without needles, and, after the injection, needles retract into the plunger, or a sheath covers the needles. Follow the manufacturer’s instructions for proper use of these systems.

Procedure for Aspirating from an Ampule 1. Identify the patient. 2. Wash your hands and put on gloves. 3. Select and assemble the appropriately sized needle and syringe (use filter needle with glass ampule if the medication requires it). 4. Remove the liquid from the neck of the ampule by flicking it or swinging it

A

B

quickly in a downward, spiraling motion while holding it by the top (Fig. 9-8A). 5. Tap around the neck of the ampule. 6. Protect your fingers with gauze if the ampule is made of glass. 7. Carefully break off the top of the ampule (for a plastic ampule twist the top) (see Fig. 9-8B).

C

FIGURE 9-8. continued

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Chapter 9—Injections

8. Aspirate fluid from the ampule (see Fig. 9-8C). 9. Remove any air from the syringe as needed.

10. Clean up and dispose of working needle and ampule in accordance with your institution’s policy for disposing of contaminated materials and sharp objects (see Chapter 2).

Procedure for Aspirating from a Vial 1. Identify the patient. 2. Wash hands and put on gloves. 3. Disinfect the top of the vial with an alcohol pad. 4. Select a syringe with a volume twice the required amount of drug or solution and add the needle. 5. Draw up as much air as the amount of solution that will be aspirated. 6. Insert the needle into the top of the vial and turn upside down (Fig. 9-9A).

8. Aspirate the required amount of solution. Note: Make sure the tip of the needle is below the fluid surface. 9. Pull the needle out of the vial. 10. Remove air from the syringe as needed (see Fig. 9-9C). 11. Clean up and dispose of materials in accordance with your institution’s policy for disposing of contaminated materials and sharp objects (see Chapter 2).

7. Push air out of the syringe into the vial (see Fig. 9-9B).

A FIGURE 9-9.

B

C

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Procedure for Administering an Intradermal Injection 1. Identify the patient. 2. Wash hands and put on gloves. Epidermis

3. Select a tuberculin syringe with a 26- or 27-gauge needle: 1⁄2 to 5⁄8 inch long is generally used. 4. Using aseptic technique, withdraw the appropriate amount of medication from the vial or ampule. 5. With the patient sitting up, have him or her extend the forearm and lay it on a flat surface with the ventral side exposed. 6. Cleanse the surface of the ventral forearm about two to three fingerbreadths distal to the antecubital space using an alcohol pad. Note: Be sure the test site is free of hair and lesions. Allow the skin to dry completely before administering the injection. 7. While holding the patient’s forearm in your hand, stretch the skin taut with your thumb. 8. With your free hand, hold the needle at a 15-degree angle to the patient’s arm, with its bevel facing up. 9. Insert the needle about 1⁄8 inch below the epidermis (Fig. 9-10). Stop when the needle bevel is beneath the skin, and inject the antigen slowly. You should feel some resistance as you do this, and a wheal or bleb should form as you inject the antigen. If no wheal forms, you have injected the antigen too deeply; withdraw the needle and administer

Dermis Subcutaneous tissue

FIGURE 9-10.

another test dose at least 2 inches from the first site. 10. Withdraw the needle at the same angle at which it was inserted. 11. Do not rub the site. This could cause irritation of the underlying tissue and may affect the test results. 12. Dispose of the syringe and needle according to your institution’s policy regarding disposal of contaminated items and sharp objects (see Chapter 2). 13. Document which agents were given, including the lot number and expiration date; where, how (which specific injection method), and when they were given; and by whom. 14. Assess the patient’s response in 24 to 48 hours. Note: In patients hypersensitive to the test antigen, a severe anaphylactic response can result. This requires immediate epinephrine injection and other emergency resuscitation procedures. Be especially alert after giving a test dose of penicillin or tetanus antitoxin.

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Procedure for Administering a Subcutaneous Injection 1. Identify the patient. 2. Wash hands and put on gloves. 3. Select a 2- to 3-mL syringe with a 24- to 26-gauge needle that is 3⁄8 to 1 inch long, depending on the amount of subcutaneous fat.

Epidermis

Note: A longer needle is needed for an obese adult, a shorter needle for a thin child.

Dermis Subcutaneous tissue

4. Using aseptic technique, withdraw the appropriate amount of medication from the vial or ampule. 5. Select an appropriate site. 6. Rotate sites according to a planned schedule for patients who require repeated injections. Use different areas of the body unless contraindicated by the specific drug. 7. Position and drape the patient. 8. Cleanse the injection site with a sterile alcohol pad, beginning at the center of the site and moving outward in a circular motion. Note: Allow the skin to dry so that alcohol is not introduced into subcutaneous tissues as the needle is inserted. 9. With the nondominant hand, pinch the skin around the injection site. 10. Insert the needle with the bevel facing up at a 45-degree angle (Fig. 9-11). If a fat fold is more than 1 inch, the needle may be injected at a 90-degree angle. 11. Release the patient’s skin to avoid injecting into compressed tissue and irritating nerve fibers. 12. Pull back on the plunger slightly. If no blood is aspirated, begin injecting the

Muscle

FIGURE 9-11.

drug slowly. If blood appears on aspiration, withdraw the needle, prepare another syringe, and repeat the procedure. 13. After injection, remove the needle gently but quickly at the same angle used for insertion. 14. Cover the site with an alcohol sponge or sterile gauze pad and massage the site gently (unless contraindicated [e.g., heparin]) to distribute the drug and facilitate absorption. 15. Remove the sponge and check the injection site for bleeding. 16. Dispose of the syringe and needle according to your institution’s policy regarding disposal of contaminated items and sharp objects (see Chapter 2). 17. Document the medication given, including the lot number and expiration date; where, how (specific injection method), and when it was given; and by whom.

Chapter 9—Injections

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SPECIAL CONSIDERATIONS ADMINISTERING INSULIN Note: To establish more consistent blood levels, rotate insulin injection sites within anatomic regions. Absorption varies from one region to another. Preferred insulin injection sites are the arms, abdomen, thighs, and buttocks. 1. Make sure the type of insulin, dose, and syringe are correct. 2. When combining different types of insulin in a syringe, make sure they are compatible. Regular insulin can be mixed with all types. 3. Before drawing up insulin suspension, gently roll and invert the bottle to ensure even particle distribution. Do not shake the bottle, because this can cause foam or bubbles to develop, changing the potency and altering the dose.

ADMINISTERING HEPARIN Note: ■ The preferred site for heparin injections is the lower abdominal fat pad, 2 inches beneath the umbilicus, between the iliac crests. Injecting heparin into this area, which is not involved in muscular activity, reduces the risk of local capillary bleeding. Always rotate the sites from one side to the other. ■

Do not administer any injections within 2 inches of a scar, bruise, or the umbilicus.

■

Do not aspirate to check for blood return because this may cause bleeding into the tissues at the site.

■

Do not rub or massage the site after the injection. Rubbing can cause localized minute hemorrhages or bruises.

■

If the patient bruises easily, apply ice to the site for the first 5 minutes after the injection to minimize local hemorrhage.

Procedure for Administering an Intramuscular Injection 1. Identify the patient. 2. Wash hands and put on gloves. 3. Select a 2- to 5-mL syringe with an 18- to 22-gauge needle 1 to 2 inches in length, depending on the injection site and the amount of muscle mass of the patient.

4. Using aseptic technique, withdraw the appropriate amount of medication from the vial or ampule and then draw about 0.2 mL of air into the syringe. 5. Select an appropriate intramuscular site. 6. Position and drape the patient. continued

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Chapter 9—Injections

7. Cleanse the injection site with a sterile alcohol sponge, beginning at the center of the site and moving outward in a circular motion. Allow the skin to dry so that alcohol is not introduced into subcutaneous tissues as the needle is inserted.

Air lock Medication

8. With the thumb and index finger of your nondominant hand, press down and stretch the skin of the injection site. Note: This reduces the thickness of subcutaneous tissue that must be pierced to reach the muscle. This is required in an obese patient. If the patient is emaciated, raise the underlying muscle mass by pinching the tissue between the thumb and index finger. 9. Position the syringe at a 90-degree angle to the skin surface, with the needle a couple of inches from the skin. Quickly and firmly thrust the needle through the skin and subcutaneous tissue deep into the muscle (Fig. 9-12). 10. Hold the syringe with your nondominant hand, if desired. Pull back slightly on the plunger with your dominant hand. If no blood is aspirated, place your thumb on

Epidermis

Air lock Medication

FIGURE 9-13.

the plunger rod and slowly inject the medication into the muscle. Note: A slow, steady injection rate allows the muscle to distend gradually and accept the medication under minimal pressure. There should be little or no resistance against the force of injection. The air bubble added to the syringe when it was prepared should follow the medication into the injection site to create an air block and prevent tracking of the medication back into the subcutaneous tissue (Fig. 9-13). 11. If blood appears in the syringe on aspiration, the needle is in a blood vessel. If this occurs, withdraw the needle, prepare another injection with new equipment, and inject another site. Do not inject the bloody solution. (Follow your institution’s policy for disposal of contaminated items and sharp objects.)

Dermis Subcutaneous tissue Muscle

FIGURE 9-12.

12. After the injection, gently but rapidly remove the needle at a 90-degree angle. 13. Cover the injection site immediately with an alcohol sponge or sterile gauze pad, apply gentle pressure and, unless contraindicated, massage the muscle to

Chapter 9—Injections help distribute the drug and promote absorption. 14. Remove the alcohol sponge and inspect the injection site for signs of active bleeding. If bleeding continues, apply pressure to the site. 15. Dispose of the syringe and needle according to your institution’s policy

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regarding disposal of contaminated items and sharp objects. (see Chapter 2). 16. Document the medication given, including the lot number and expiration date; where, how (specific injection method), and when it was given; and by whom.

Procedure for Administering a Z-track Intramuscular Injection Note: The Z-track method of intramuscular injection prevents leakage of medication back into subcutaneous tissue after the injection is given. It is used with certain drugs—primarily iron preparations—that irritate or discolor subcutaneous tissue. Lateral displacement of the skin before injection helps seal the drug in the muscle after the skin is released. This procedure requires careful attention to technique, because leakage into subcutaneous tissue can cause patient discomfort or may permanently stain tissue if an iron preparation is being given. This type of injection is given only in the outer upper quadrant of the buttocks.

6. Position and drape the patient in the prone or lateral position. 7. Cleanse the area with a sterile alcohol pad. 8. Displace the skin laterally by pulling it about 1⁄2 inch away from the injection site (Fig. 9-14A and B).

Air lock Medication

1. Identify the patient. 2. Wash hands and put on gloves. 3. Select a 3- to 5-mL syringe with two 20-gauge needles at least 2 inches long. 4. Using aseptic technique, withdraw the appropriate amount of medication from the vial or ampule and then draw about 0.2 to 0.5 mL of air into the syringe. Remove the first needle and attach the second needle to prevent introduction of medication from the outside of the first needle into the subcutaneous tissue. Note: For this type of injection, be sure to provide privacy for the patient. 5. Select an appropriate site in an upper outer buttock.

During injection

A

Injection tract seals as skin is released Skin Subcutaneous tissue Air lock

Muscle

Medication After release

B FIGURE 9-14. continued

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Chapter 9—Injections

9. Insert the needle into the muscle at a 90-degree angle. 10. Pull back on the plunger slightly. If no blood is aspirated, inject the drug slowly, followed by the air, which helps clear the needle and prevents tracking of the medication through the subcutaneous tissue. 11. Encourage the patient to walk or move around in bed to facilitate absorption from the injection site. 12. Dispose of the syringe and needle according to your institution’s policy regarding disposal of contaminated items (see Chapter 2). 13. Document the medication given, including the lot number and expiration date; where, how (specific injection method), and when it was given; and by whom.

Note: Alternate gluteal sites to avoid repeated injections in the same site. If the patient is on bed rest, encourage active range of motion exercises or perform passive range of motion exercises to facilitate absorption from the injection site. Note: If you must inject more than 5 mL of solution, divide the solution and inject it at two separate sites unless the gluteal muscles and vastus lateralis are well developed. Intramuscular injections can traumatize local muscle cells, causing elevated serum levels of enzymes (creatine phosphokinase [CPK]) that can be confused with the elevated enzyme levels resulting from damage to cardiac muscle, as in myocardial infarction. Oral or intravenous routes are preferred for administration of drugs that are poorly absorbed by muscle tissue, such as phenytoin, digoxin, chlordiazepoxide, diazepam, and haloperidol.

Caution: Never inject more than 5 mL into a single site using the Z-track method.

SPECIAL CONSIDERATIONS PEDIATRIC PATIENTS ■

Subcutaneous injections are usually administered into the thigh of infants and into the deltoid area of older children.

■

The preferred sites for intramuscular injections are the anterolateral aspect of the upper thigh and the deltoid muscle of the upper arm.

■

Among most infants, the anterolateral thigh provides the largest muscle mass and is therefore the recommended site.

■

The deltoid can also be used with the thigh when multiple injections (such as vaccinations) are needed.

■

In toddlers and older children, the deltoid may be used if the muscle mass is adequate.

■

Never use the gluteal muscles, which develop from walking, as the injection site for children younger than age 3 or for those who have been walking less than a year.

Chapter 9—Injections ■

The buttock should not be used routinely in children because of the risk of sciatic nerve injury (Bergeson, 1982).

FOLLOW-UP CARE AND INSTRUCTIONS ■

Immediately dispose of needle and syringe properly in an appropriate needle disposal (sharps) container.

Caution: Never recap needles. It is important to follow this advice diligently to help prevent the 600,000 to 800,000 needlesticks and other percutaneous injuries reported in the United States each year among the 8 million health care workers. (Henry, 1995; EPINet, 1999). ■ Monitor the patient’s response, especially after injections of large doses of antibiotic. Patient should be monitored for approximately 30 minutes for signs of anaphylaxis. ■

Instruct the patient to report a new onset of fever, joint pain, shortness of breath, or rash. Also, tenderness, erythema, or ecchymosis at the injection site should be reported to the health care provider.

REFERENCES Bergeson PS, Singer SA, Kaplan AM: Intramuscular injections in children. Pediatrics 70:944-948, 1982. Brokensha G: The hollow needle: Inappropriate injection in practice. Aust Prescr 22:145-147, 1999. EPINet: Exposure prevention information network data reports. University of Virginia, International Health Care Worker Safety Center, 1999. Feldmann H: History of injections. Laryngorhinootologie 79:239-246, 2000. Henry K, Campbell S: Needlestick/sharps injuries and HIV exposures among health care workers: national estimates based on a survey of U.S. hospitals. Minn Med 78:1765-1768, 1995. Howard-Jones N: The origins of the hypodermic medications. Sci Am 224:96-102, 1971.

BIBLIOGRAPHY American Diabetes Association: Insulin administration. Diabetes Care 23(suppl 1):S86, 2000. Centers for Disease Control and Prevention: General recommendations on immunization recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Recomm Rep 43(RR-01):1-38, 1994. D’Angelo HH, Welsh NP (eds): Medication Administration and IV Therapy Manual, 2nd ed. Springhouse, Pa, Springhouse, 1993.

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Chapter 9—Injections De Vries PG, Henning RH, Hogerzeil HV: WHO Guide to Good Prescribing: The Use of Injections. World Health Organization, 1995. Available at: http:// www.med.rug.nl/pharma/ggp.htm Elkin MK, Perry AG, Potter PA: Nursing Interventions and Clinical Skills, 2nd ed. St. Louis, CV Mosby, 1999. Gilles FH, French JH: Postinjection sciatic nerve palsies in infants and children. J Pediatr 58:195-204, 1961. Newton M, Newton D, Fudin J: Reviewing the “big three” injection routes. Nursing 22:34-42, 1992. Smith SF, Duell DJ, Martin BC: Clinical Nursing Skills: Basic to Advanced Skills. Upper Saddle River, NJ, Prentice Hall Health, 2000.

Chapter

10

Recording an Electrocardiogram Richard R. Rahr and Salah Ayachi

PROCEDURE GOALS

AND

OBJECTIVES

Goal: To perform an electrocardiogram (ECG) safely and accurately. Objectives: The student will be able to …

•

Describe the indications, contraindications, and rationale for performing an ECG.

•

Identify and describe potential complications associated with performing an ECG.

•

Describe the essential anatomy and physiology associated with performing an ECG.

•

Identify the materials necessary for performing an ECG and their proper use.

•

Identify the proper steps for performing an ECG.

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Chapter 10—Recording an Electrocardiogram

FIGURE 10-1. Electrocardiographic methodology in 1911. (Redrawn from Rawlings CA: Electrocardiography. Redmond, Wash, SpaceLabs, 1991, p 26.)

BACKGROUND AND HISTORY In 1790 Salvori demonstrated that stimulation of a charged glass rod attached to a frog’s leg muscle causes contraction of the muscle, as if the frog willed it to do so. In 1855 Kollickes and Mueller dissected a frog’s heart and attached it to the leg muscle; they noted the frog’s leg twitched with each heartbeat. In 1880 Ludig and Waller developed a crude capillary electrometer and recorded the electrical activity of the heartbeat from the skin surface. It was not until 1901 that Einthoven developed a machine that passed light over a moving wire and recorded the PQRSTU waveform (Fig. 10-1). He was the first to develop the first three leads (I, II, and III) that make up the equilateral triangle that today bears his name.

INDICATIONS Numerous technologic advances (cardiac catheterization, echocardiography, nuclear medicine imaging, and magnetic resonance imaging [MRI]) in the study of heart function notwithstanding, the 12-lead ECG continues to be an effective and inexpensive method to screen for heart disease and monitor patients with acute and chronic heart conditions. Some of these conditions include the following:

Chapter 10—Recording an Electrocardiogram ■

Ischemic heart disease, including myocardial infarction

■

Heart block

■

Dysrhythmias (including wide ventricular tachycardia)

■

Electrolyte disturbances

■

Abnormality in chamber size or myocardial hypertrophy

The use of the 12-lead ECG is essential in the following scenarios: ■ At sites of accidents or emergency calls, it enables the paramedic to identify heart disease with 62% to 90% specificity and 71% to 90% sensitivity in the presence of chest pain (Taylor, 1998). ■

It gives hospital personnel warning signs of a patient’s condition during transport to the hospital for treatment with thrombolytics or for control of advanced arrhythmias. In some instances, paramedics are allowed to administer thrombolytics prior to arrival at the hospital.

The 12-lead ECG plays a critical role in reducing morbidity and mortality in patients with coronary artery disease, because it enables the practitioner to detect early danger signs and administer reperfusion medications.

CONTRAINDICATIONS The only relative contraindications to performing an ECG are as follows: ■ Concern that the equipment may be malfunctioning ■

Hypersensitivity to the electrode adhesive

POTENTIAL COMPLICATIONS ■

The most common complication is misinterpretation of the 12-lead ECG. A tracing can be misinterpreted as being “normal” when it is not (i.e., false negative), leading to acquiescence and lowering of the practitioner’s index of suspicion, thus failure to intervene, and possibly to patient demise. The lesson is that a “normal ECG” does not preclude underlying pathology.

■

Errors in interpretation could actually be due to errors in lead placement. It is incumbent on the practitioner to repeat the ECG should unusual waveform patterns for a set of leads appear.

■

Because electrodes are attached to the patient’s skin, either by adhesives or suction, skin damage may result, especially in elderly or diabetic patients, potentially leading to infections.

■

Although extremely unlikely, it is possible that a patient could receive an electrical shock if there is a short in the wiring. Electrocardiographs today are protected by a third ground wire to prevent such events.

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Chapter 10—Recording an Electrocardiogram

Receiving chambers

Right atrium

Left ventricle

Right ventricle

FIGURE 10-2.

Left atrium

Pumping chambers

Anatomy of the heart.

REVIEW OF ESSENTIAL ANATOMY AND PHYSIOLOGY A review of the anatomy and physiology of the heart is necessary for proper understanding of the 12-lead ECG. The heart is a complex organ whose primary function is to pump blood through the pulmonic and systemic circulations. Four muscular chambers—right and left atria (collecting chambers) and right and left ventricles (pumping chambers)—compose the heart (Fig. 10-2). An intricate network of specialized muscle cells coordinates the sequential contractions of the chambers to make it an effective pump. The pulmonary artery arises from the right ventricle, whereas the aorta originates from the left ventricle. Each of these large vessels has a valve (pulmonic and aortic, respectively) that opens to accommodate ejection of blood during systole and closes to prevent backward flow during diastole. Atria and ventricles are separated by a valve—the tricuspid between the right atrium and ventricle, and the mitral between the left atrium and ventricle. As in the case of the pulmonic and aortic valves, the tricuspid and mitral valves open to accommodate forward flow and close to prevent retrograde flow. Unlike the pulmonic and aortic valves, the tricuspid and mitral valves open during diastole and close during systole. The left main and right coronary arteries arise from the root of the aorta. The coronary sinus drains venous blood into the right atrium.

Chapter 10—Recording an Electrocardiogram Superior vena cava Left atrium Right atrium

Pulmonary artery Aorta

Blood out to systemic arteries and coronary arteries

Blood in

Blood out to lungs Inferior vena cava

FIGURE 10-3.

The heart box.

Poorly oxygenated blood returning from the systemic circulation, through the superior and inferior venae cavae, to the right atrium enters the right ventricle in large part (70%) by gravity; atrial contraction contributes only 30% to ventricular filling during diastole. The right ventricle pumps blood into the pulmonary artery and the lungs where it is oxygenated and then returned to the left atrium by the pulmonary veins. As in the case of the right side of the heart, atrial contraction contributes only 30% of the blood that enters the left ventricle during diastole. The left ventricle pumps blood into the aorta and the systemic circulation, including the coronary arteries, which originate from the base of the aorta and supply the myocardium with oxygen-rich blood mostly during diastole (Fig. 10-3). The larger and thicker walled left ventricle maintains the pressure necessary to effect forward flow to the systemic circulation. Deoxygenated blood from the myocardium returns to the right atrium via the coronary sinus. The electrical pathways (or conduction system) (Fig. 10-4) are essential to the coordinated activity of the heart. The sinoatrial (SA) node, located near the junction of the superior vena cava and the right atrium, has an intrinsic (spontaneous) electrical discharge of 60 to 100 cycles per minute, whereas the atrioventricular (AV) node, located between the right atrium and the right ventricle, spontaneously discharges at 40 to 60 cycles per minute. Adjacent to the AV node and traveling through the ventricular septum are specialized fibers—His bundle, bundle branches, and Purkinje fibers—that conduct electrical impulses at a high rate of speed. Normally, the SA node initiates the electrical impulse, which rapidly spreads through internodal tracts and depolarizes the left and right atria, ultimately reaching the AV node. At this node, conduction velocity slows considerably to allow atrial activity to complete before ventricular activity begins. Following

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Chapter 10—Recording an Electrocardiogram Bachman’s bundle Atrial muscle SA node

Bundle of His

Internodal pathways AV node RBB

LA LPF

Ventricle muscle LBB

FIGURE 10-4. Electrical pattern of the heart. AV, atrioventricular; LA, left atrium; LBB, left bundle branch; LPF, left posterior fascicle; RBB, right bundle branch; SA, sinoatrial.

this delay, the impulse moves very rapidly through the bundle of His and its branches (the left has two fascicles) and the Purkinje fibers, resulting in the nearly simultaneous depolarization of the right and left ventricles (Fig. 10-5). The atria and ventricles are separated by a fibrous ring that serves to insulate the chambers from their respective activities and permit spread of electrical activity from atria to ventricles only through the AV node area. The system allows the atria and ventricles to beat synchronously, resulting in effective and efficient pumping activity. The electrical activity of the heart can be measured on the surface of the body using an electrocardiograph, thereby producing ECG tracings that consist of repeating waveforms (PQRST) in which the P wave represents depolarization of atrial tissues, the QRS complex represents depolarization of the ventricles, and the T wave represents repolarization of the ventricles; no waveform is noted that represents atrial repolarization (Fig. 10-6).

PATIENT PREPARATION Patient preparation is important. Time should be taken to explain to the patient what the procedure entails and what the patient should expect as well as to answer any questions the patient may have. Preparing the patient’s skin helps ensure optimal conditions for recording the ECG. The following steps should be taken to prepare the patient: ■ Introduce yourself to the patient. ■

Explain the 12-lead electrocardiography procedure, and proceed by draping the patient’s chest.

Chapter 10—Recording an Electrocardiogram SA node — Primary pacemaker

Internodal tracks

Atrial muscle — P wave formed

AV node — delay area

Bundle of His

Right bundle branch

Left bundle branch

Left posterior fascicle

Purkinje cells

Muscle cells of ventricles

Left anterior fascicle

FIGURE 10-5. Electrical sequence of the normal heart. AV, atrioventricular; SA, sinoatrial.

I

aVR

V1

V4

II

aVL

V2

V5

III

aVF

V3

V6

II

FIGURE 10-6.

Electrocardiographic 12-lead tracing.

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120

Chapter 10—Recording an Electrocardiogram ■

Identify the six precordial leads (you may choose to mark them with a felt-tipped pen).

■

If necessary, shave the areas where the electrodes are to be placed.

■

Use alcohol pads to cleanse the skin and, if necessary, rub with a mild abrasive pad.

■

Use alcohol pads again to remove any residue.

■

Attach the adhesive pads and connect the electrodes.

Materials Utilized for Electrocardiography ■

The machine used to do routine 12-lead ECGs is a standard electrocardiograph mounted on a cart that can be easily wheeled from one location to another. Modern systems have a resting electrocardiographic analysis system with quick reference readout.

■

Electrodes for the six precordial sites

■

Razor to shave hair from a male patient’s chest, if necessary.

■

Alcohol to clean skin surface

■

Felt pen to mark site (optional)

■

Abrasive pad to remove epidermal skin layer at electrode sites; pads are used to gently remove felt-pen marks.

Procedure for Performing the Electrocardiogram Note: The following steps are for performing a routine 12-lead ECG at the bedside. 1. Assemble supplies (leads, alcohol, abrasive pads, etc.). 2. Verify the order on the patient’s chart. 3. Verify the patient’s identity. 4. Wash hands. 5. Plug in power cord and turn on electrocardiograph. 6. Position the patient in a comfortable supine position and provide a drape or gown to maintain the patient’s modesty

yet afford adequate access to the patient’s chest for lead placement. 7. Cleanse skin at the six precordial sites. 8. Attach limb and precordial leads (refer to Figures 10-7 and 10-8 for correct lead placement). 9. Confirm that all leads are connected. 10. Enter patient’s information. 11. Ask the patient to lie quietly for 30 seconds. 12. Press the 12-lead (or the record ECG) button to record the tracing.

Chapter 10—Recording an Electrocardiogram Right

121

Left

R.A.

L.A.

V1

R.L. (ground)

V5 V6 V4 (mid(midaxillary) clavicular)

V2

V3

L.L.

V1 - Fourth intercostal space at right border of sternum. V2 - Fourth intercostal space at left border of sternum. V4 - At the mid-clavicular line and the inter-space in which the apex is located (the 5th intercostal space is used if the apex is not palpable). V3 - Midway between positions 2 and 4. V5 - At the anterior axillary line on a horizontal level with V4. V6 - At the mid-axillary line on the same horizontal level as V4 and V5.

Spine

Heart

L.V.

R.V.

V6 V5

Chest wall

V1

V2

V3

V4

FIGURE 10-7.

Sternum

FIGURE 10-8. continued

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Chapter 10—Recording an Electrocardiogram

13. “Acquired data” message will appear; wait for “ECG acquisition complete” message to appear. 14. Enter number of extra copies desired. 15. Print report to attach to chart and for cardiology reading station.

17. Enter your name, date, and identification number. 18. Remove electrodes and adhesive pads 19. Assist patient with cleaning up and redressing, as necessary. 20. Dispose of used supplies.

16. Press “Store” and “Data in store” to store data for comparison with future tracings.

SPECIAL CONSIDERATIONS In case the patient is unable to remain in one position for 30 seconds because of pain, shortness of breath, or confusion, the operator may need assistance to complete the procedure. Similarly, assistance may be required if the patient is a child who is anxious about or fearful of the equipment or procedure.

FOLLOW-UP CARE AND INSTRUCTIONS ■

No follow-up care is necessary provided the skin has not been damaged by the adhesive pads.

■

Patients should be given an estimate of the time it takes before they are given the results and interpretation of the ECG.

REFERENCE Taylor RV, Key CB, Trach M: Advanced Cardiac Care in the Streets. Philadelphia, Lippincott, 1998.

BIBLIOGRAPHY Constant J: Essentials of Learning Electrocardiography: A Complete Course for the Non-Cardiologist. New York, Parthenon, 1997. Dubin D: Rapid Interpretation of EKGs. Tampa, Fla, Cover, 1996. Goldschlager N, Goldman MJ: Electrocardiography: Essentials of Interpretation. Los Altos, Calif, Lange Medical, 1984. Lewis KM, Handal KA: Sensible ECG Analysis. Albany, NY, Delmar, 2000. Lipman BC: ECG Pocket Guide. Chicago, Ill, Year Book Medical, 1987. Murphy KR, Pelton JJ: ECG Essentials. Chicago, Ill, Quintessence, 1991. Rawlings CA: Electrocardiography. Redmond, Wash, SpaceLabs, 1991. Schamroth L: An Introduction to Electrocardiography. Oxford, England, Blackwell Scientific, 1976.

Chapter

11

Exercise Stress Testing for the Primary Care Provider Charles S. King

PROCEDURE GOALS

AND

OBJECTIVES

Goal: To identify appropriate candidates for exercise stress testing and to administer the test safely. Objectives: The student will be able to …

•

Describe the indications, contraindications, and rationale for performing exercise stress testing.

•

Identify and describe common complications associated with exercise stress testing.

•

Describe the essential anatomy and physiology associated with the effective and safe performance of exercise stress testing.

•

Identify the necessary materials and their proper use for performing an exercise stress test.

•

Identify the important aspects of patient care after an exercise stress test.

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Chapter 11—Exercise Stress Testing for the Primary Care Provider

BACKGROUND AND HISTORY Despite advances in disease prevention, coronary artery disease (CAD) remains a major cause of death and disability in the United States. There are considerable costs associated with treating this disease, which are compounded by expenses related to time lost from work and lost wages. Since the 1950s, electrocardiographic analysis during patient exercise has been employed in the pursuit of objective evidence for the presence or progression of CAD. More recently, and perhaps more importantly, the role of exercise testing has taken on the goal of predicting patient outcomes. The prognostic value of the Duke treadmill scoring system has added considerable dimension to cardiac stress testing. Although not perfectly applicable to all patients under consideration for stress testing, its usefulness in estimating prognosis in a large segment of patients has been well established. The physiologic stress of exercise can elicit cardiovascular abnormalities not present at rest. Although exercise testing was initially used as a diagnostic tool, it is also a powerful predictor of subsequent cardiac events. Exercise stress testing provides a controlled environment for observing the effects of increased myocardial oxygen demand and can be used to determine the adequacy of cardiac perfusion. The exercise stress test is a valuable tool for detecting CAD and for evaluating medical therapy, percutaneous or surgical revascularization, and cardiac rehabilitation after myocardial infarction. Electrocardiographic changes during exercise can provide evidence of ischemia if significant stenosis from CAD is present. Healthy persons who are asymptomatic may be considered candidates for exercise testing if they intend to engage in strenuous or high-risk occupations. The American College of Sports Medicine (ACSM) recommends an exercise test for all women 50 years of age and older and all men 40 years of age and older who plan to engage in vigorous exercise. The ACSM does not recommend exercise testing for asymptomatic, healthy persons who are not planning vigorous exercise, regardless of the person’s age (Pate, 1991). In addition to the standard exercise stress test, other methods of cardiovascular stress testing include scintigraphy and echocardiography. Exercise stress scintigraphy uses a radioactive tracer to enhance abnormal areas of myocardial blood flow and can be performed with pharmacologic agents instead of exercise if a patient’s condition warrants. Echocardiography has been used in combination with exercise or pharmacologic stress testing as another form of noninvasive cardiac evaluation.

INDICATIONS By exposing the cardiopulmonary system to increased metabolic demands using standardized methods and protocols of stress, the clinician is provided a useful tool for detecting the initial presence of cardiopulmonary pathology and for assessing the efficacy of various therapies and rehabilitation programs.

Chapter 11—Exercise Stress Testing for the Primary Care Provider Employing electrocardiographic monitoring and patient vital signs alone or in concert with established and developing imaging modalities, stress testing adds a valuable adjunct to the well-thought-out history and physical examination. Cardiac stress testing is indicated as follows: ■

To establish the initial diagnosis of obstructive CAD

■

To stratify risk and monitor treatment of patients with previously diagnosed or treated CAD

■

To screen asymptomatic individuals (CAD risks or occupations that place the public at risk)

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To assess exercise capacity in patients with va1vular, congenital abnormalities or congestive heart failure (CHF)

■

To document and monitor therapy in those with exercise-related heart dysrhythmia

As with all laboratory testing, exercise stress testing should be used to augment an already high clinical suspicion of disease that is based on a quality history and physical examination. Accordingly, the rationale for using exercise stress testing in the primary care setting should be based on the “predictive value” of the given test. Attention should be paid to the prevalence of the disease in the patient population under consideration (i.e., the pretest probability of detecting pathology in a given patient). The sensitivity and specificity of exercise stress testing with electrocardiographic monitoring alone have been validated for its use in detecting CAD by comparison of ST segment changes (depression or elevation) with the gold standard of coronary angiography (Gianrossi, 1989). True positives— that is, the percentage of patients with disease who have electrocardiographic changes indicative of ischemia—are the measures of sensitivity in exercise stress testing, which in the general patient population varies from 40% to 90% (Fletcher, 1992). The sensitivity of exercise stress testing in detecting cardiac pathology other than CAD is less clear. The occurrence of false negatives—that is, tests in which there is an absence of diagnostic electrocardiographic changes in the presence of true CAD—can be minimized by sound test candidate selection and practicing good testing technique (e.g., achieving target heart rate, getting quality data). The specificity of exercise stress testing with electrocardiographic monitoring alone, described as the percentage of normal patients (i.e., those without CAD) who manifest no electrocardiographic changes indicative of CAD, is reported to be 84% (Fletcher, 1992). False-positive results—that is, tests in which electrocardiographic changes suggest CAD that cannot be substantiated by subsequent coronary angiography—are often associated with patient selection (gender), electrocardiographic abnormality (left ventricular hypertrophy), Q waves at baseline, and associated drug therapy (digoxin). Both sensitivity and specificity are improved when the pretest probability of detecting the target pathology in a group of patients is high at the onset. Prevalence tables for a variety of illnesses are published and usually broken

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Chapter 11—Exercise Stress Testing for the Primary Care Provider Pretest Probability of Coronary Artery Disease by Age, Gender, and Symptoms

Table 11.1

AGE (yr) 30-39 40-49 50-59 60-69

GENDER Men Women Men Women Men Women Men Women

TYPICAL— DEFINITE ANGINA PECTORIS Intermediate Intermediate High Intermediate High Intermediate High High

ATYPICAL— PROBABLE ANGINA PECTORIS Intermediate Very low Intermediate Low Intermediate Intermediate Intermediate Intermediate

NONANGINAL CHEST PAIN Low Very low Intermediate Very low Intermediate Low Intermediate Intermediate

ASYMPTOMATIC Very low Very low Low Very low Very low Very low Low Low

High, >90%; intermediate, 10%-90%; low, 5 mm on transvaginal sonography (TVS) in a postmenopausal woman

Adapted from Albers (2004), Mounsey (2002), Stenchever (2001), and Zuber (2001).

Table 34.2

Contraindications*

Absolute

Perform in hospital setting

During menses Possibility of pregnancy Uncooperative patient History of unstable angina Moderate to severe cervical stenosis Coagulation disorder or on anticoagulant or antiplatelet therapy Morbid obesity

*Rule out cervicitis and pelvic inflammatory disease prior to biopsy in all patients. Adapted from Albers (2004), Mounsey (2002), and Stenchever (2001).

patient to the emergency room. If no bleeding is seen, the patient can be discharged home. Be certain the patient has someone to monitor her at home for the next 24 hours, and instruct the patient to call with any fever, excessive pain, or blood loss. Wait 6 to 8 weeks for uterine healing before attempting biopsy again. ■

Inadequate sample: If specimen is reported as inadequate, repeat the procedure or use another method of evaluation, such as D&C, hysteroscopy, or transvaginal sonography (TSV), or a combination.

■

Infection: Post-procedure infection is rare if the procedure is performed properly and there is no pre-existing infection. Patients should notify the office immediately if fever or pain develops. Antibiotic prophylaxis for endocarditis is considered unnecessary (Mounsey, 2004), but patients at risk may be treated with tetracycline (500 mg bid for 4 days) following the procedure, at the clinician’s discretion (Zuber, 2001).

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Chapter 34—Endometrial Biopsy Fundus Fallopian tube

Ovary

Internal os

Myometrium Endometrium

External os

Vaginal canal

FIGURE 34-1. Anatomy of the uterus and surrounding structures.

REVIEW OF ESSENTIAL ANATOMY AND PHYSIOLOGY ANATOMY Figure 34-1 illustrates the anatomy of the uterus and its surrounding structures.

PHYSIOLOGY

AND

PATHOPHYSIOLOGY

The endometrium consists of two layers, the stratum basale and the stratum functionale. The stratum functionale cells proliferate under the influence of estrogen and desquamate at the time of menses. The thickness of the endometrium varies throughout the menstrual cycle from 1 to 2 mm at the time of menses to 4 mm in the early proliferative (follicular) phase, to about 12 mm at ovulation, and maintaining 12 mm during an appropriate secretory (luteal) phase. Hyperplasia is defined as the abnormal proliferation of endometrial cells usually caused by estrogen unopposed by the action of progesterone. The presenting symptom is AUB. Endometrial hyperplasia is described as mild, moderate, or complex and in histological terms such as cystic, adenomatous, or glandular. The major findings on endometrial biopsy sample are as follows (Canavan, 1999): ■ Proliferative, secretory benign or atrophic endometrium ■

Simple or complex (adenomatous) hyperplasia without atypia

■

Simple or complex (adenomatous) hyperplasia with atypia (considered precancerous)

■

Endometrial carcinoma

Chapter 34—Endometrial Biopsy

PATIENT PREPARATION The EMB is a safe and quick procedure. Clarify the procedure completely to the patient and discuss possible alternative techniques. Endometrial evaluation can be achieved by a variety of methods, so it is important that the patient understands the choices and reasons for the chosen procedure. Obtain informed consent. Explain to the woman that she may experience slight cramping during and after the biopsy, but it is not painful. The patient may take a non-steroidal anti-inflammatory drug (NSAID) 1 hour before the biopsy to reduce any discomfort. The patient can expect to remain in the office for about 1 hour after the procedure, but she may then drive and resume normal daily activities.

Materials Utilized for Endometrial Biopsy The choice of equipment depends on the reason for the biopsy and clinician preference. The smaller the canula type, the more comfortable for the patient but less tissue will be obtained. Conversely, the larger curettes acquire more tissue sample but produce more discomfort. For evaluation of possible malignancy, the biopsy should be preceded by endocervical curettage (ECC). For endometrial sampling, the choices include: ■ Novak curette: This is a nondisposable rigid canula made of stainless steel that attaches to a syringe plunger for suction. The tissue sample is drawn through the canula into the syringe. ■

Pipelle aspirator: This is a disposable device made of clear, flexible polypropylene sheath, 23 cm in length with a small opening in the distal end. It has an inner plunger that when pulled back provides suction. It is marked so that the uterus cavity can be measured and biopsy performed in one step.

■

Tis-U-Trap set: This is a sterile plastic disposable device that requires external suction. It consists of a clear plastic tissue collection chamber with a flat filter and one of several types of curettes. Endometrial tissue is collected directly into the collection chamber, thereby eliminating the need to transfer the tissue sample into another container.

■

Tao Brush: This is a narrow polypropylene brush covered by a clear protective sheath. After insertion into the uterine cavity, the sheath is pulled back to allow for sampling with the brush. The sheath is then replaced over the brush, trapping the tissue sample (Figs. 34-2 and 34-3).

■

Suction: Suction is created by a syringe or internal piston system. An external source, such as a wall or portable pump providing 25 to 27 inches Hg of negative pressure, is needed.

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Chapter 34—Endometrial Biopsy

FIGURE 34-2. Endometrial biopsy setup (from top): anesthetic, tenaculum, Novak curette, and cervical dilators.

FIGURE 34-3. Instruments (left to right): uterine sound, Novak curette, Tis-U-Trap, and Pipelle.

Chapter 34—Endometrial Biopsy ■

■

General equipment: ■

Absorbent material to go under the patient

■

Disinfectant material of choice for cleansing the cervix

■

Topical or injectable lidocaine or benzocaine for the cervix

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Labeled tissue containers with appropriate preservative (not needed if sampling device has container attached, such as the Tis-U-Trap)

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Sanitary napkins for post-procedure hygiene

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Fluid-proof gown and protective eyewear

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Unsterile gloves

Sterile equipment: ■

Gloves

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Speculum

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Uterine sound (depending on type of biopsy instrument used)

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Endocervical curette (if ECC is to be performed)

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4 × 4-inch gauze pads

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Ring forceps

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Tenaculum

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Cervical dilators (two types are available): Mechanical (unopened but available if needed)—sterile rigid metal or plastic curved rods in graduated thicknesses; Medical (particularly useful for the postmenopausal cervix)—either laminaria (sizes 2 mm through 10 mm), a natural osmotic cervical dilator made from seaweed and packaged as narrow tampon, which is inserted into the cervix 2 to 12 hours prior to the procedure to soften and open the cervix, or synthetic laminaria (Dilateria, Lamicel, Dilapan), an absorbent polyvinyl acetal sponge, impregnated with less than 500 mg of magnesium sulfate (Epsom salt) and compressed and inserted into the cervix 2 to 12 hours prior to the procedure to absorb fluid and gently open the cervix

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Anesthetic (optional)—one of the following: 2% lidocaine with epinephrine, 5 mL injected into the cervix before procedure or 0.5% to 1% lidocaine without epinephrine; 20% benzocaine spray or gel applied to cervix

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Procedure for Endometrial Biopsy 1. Put on a gown and protective eyewear. 2. Review the specific directions for equipment and sampling device being used and be certain all parts are in working order before beginning the procedure. Place the patient in the lithotomy position with her legs in stirrups and drape appropriately. Perform a bimanual examination with unsterile gloves to evaluate size and position of the uterus and the uterocervical angle. Palpate the adnexa to rule out tenderness that may indicate infection. 3. Change to sterile gloves. 4. Using a vaginal speculum, inspect the cervix for discharge, stenosis, or other abnormalities. Using ring forceps holding cotton or gauze, wipe the cervical os with water-based antiseptic. 5. Perform ECC if indicated (see later, “Supplementary and Alternative Procedures”) 6. Apply or inject anesthetic to the cervix 5 to 10 minutes prior to starting procedure. • Spray or apply gel or • Inject lidocaine at 4 o’clock and 8 o’clock positions 7. Grasp the anterior lip of the cervix with the tenaculum in a horizontal position and lock in place. To avoid lacerating the cervix, grasp enough tissue. The tenaculum is used to stabilize the cervix and uterus during the procedure. Apply gentle traction on the tenaculum to straighten the uterocervical angle. 8. Measure the depth of the uterine cavity with the uterine sound. Document uterine depth.

Note: This step is optional if biopsy device is marked for measurement. • Using moderate pressure, insert the sound through the os until gentle resistance is encountered, usually at a depth of 6 to 9 cm. Note the measurement of the uterine cavity and remove the sound. • Use dilators if it is difficult to pass the sound through the internal os. Start with the smallest dilator, progressing to the next size until the os is opened enough for the sound to pass. (This is unnecessary if medical dilators are used prior to the procedure.) 9. Collect the endometrial sample (Figs. 34-4 and 34-5). 10. Steady and straighten the cervix with slight traction on the tenaculum. 11. Insert the sampling cannula through the os being careful to avoid touching vulvar or vaginal tissue that would cause contamination. 12. Rotate the sampling cannula device between the thumb and forefinger as it passes through the os. Apply gentle pressure until it reaches the fundus, as indicated by previous measurement or by resistance, then withdraw very slightly. 13. Stabilize the sampling cannula with one hand while activating suction with the other. • If using a syringe sampling device, steadily withdraw plunger in one smooth motion, being sure not to advance the cannula or to let the plunger slide forward. • If using external suction, activate suction according to manufacturer’s instructions.

Chapter 34—Endometrial Biopsy

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Insert Pipelle

Pull plunger to create suction

Rotate Pipelle while moving in and out (Do not pull out past internal os)

Tenaculum on cervix

Novak curette

FIGURE 34-4. Endometrial biopsy using Pipelle.

14. Gently pull the cannula toward the internal os and then push it back into the uterine cavity at least four times, being careful not to withdraw past the internal os. Rotate the cannula consistently in a clockwise direction several times, and then counterclockwise, while performing the movement in all four quadrants of the endometrial cavity in a systematic fashion in a vacuuming type pattern. 15. Release suction pressure and remove the cannula. 16. Deposit the sample into an appropriate labeled and fixative-filled specimen container. With the Pipelle, use sterile scissors to cut off the tip to expel the sample.

FIGURE 34-5. curette.

Endometrial biopsy using Novak

Note: This step is not necessary with the Tis-U-Trap. continued

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17. Remove the tenaculum.

19. Remove the speculum.

18. Cleanse the vagina and cervix gently with gauze.

20. Dispose of equipment according to standard biohazard precautions.

FOLLOW-UP CARE AND INSTRUCTIONS The patient should remain in the examination room for 15 minutes and in the office for another 30 minutes. A vasovagal reaction typically occurs within the first 10 minutes after the procedure, if at all. The patient should be instructed that slight spotting and cramping is considered normal. The patient may drive after discharge from the office. Patient may be advised to take NSAIDs as needed for cramping after the biopsy, as these provide the additional benefit of antiprostaglandin activity. Acetaminophen is an acceptable option for discomfort. The patient should use sanitary napkins only and report if bleeding is heavier than her normal menses or if a fever develops. It is recommended that women refrain from sexual activity until the bleeding has stopped.

SUPPLEMENTARY AND ALTERNATIVE PROCEDURES ■

Endocervical curettage is always indicated prior to endometrial biopsy if any malignancy needs to be ruled out. ECC samples must be deposited into a separate container.

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Hysteroscopy can be used with or without concurrent biopsy.

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Transvaginal sonography may be used to assess endometrial thickness, with an endometrial stripe ≤4 mm having 96% sensitivity in ruling out endometrial cancer (Mounsey, 2002).

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Saline infusion sonography involves filling the uterine cavity with saline prior to ultrasound and allows for visualization of endometrial thickness and polyps.

REFERENCES Albers J, Hull S, Wesley R: Abnormal uterine bleeding. Am Fam Physician 69:1915-1926, 2004. Canavan T, Doshi N: Endometrial cancer. Am Fam Physician 59:3069-3077, 1999. Katz V: Diagnostic procedures. In Stenchever M, Proegemeuller W, Herbst A, Mischell D (eds): Comprehensive Gynecology, 4th ed. St. Louis: Mosby, 2001, pp 232-233.

Chapter 34—Endometrial Biopsy Mounsey A: Postmenopausal bleeding: Evaluation and management. Clin Fam Pract 4:173-192, 2002. Paraskevaidis E, Kalantaridou SN, Papadimitriou D, et al: Transvaginal uterine ultrasonography compared with endometrial biopsy for the detection of endometrial disease in perimenopausal women with uterine bleeding. Anticancer Res 22:1829-1832, 2002. Smith RA, Cokkinides V, Eyre HJ: American Cancer Society guidelines for the early detection of cancer, 2005. CA Cancer J Clin 55:31-44, 2005. Zuber T: Endometrial biopsy. Am Fam Physician 63:1131-1135, 2001.

BIBLIOGRAPHY American College of Nurse-Midwives: Clinical Bulletin No. 5, Endometrial Biopsy, 2001. Accessed 6/2/2005: http://www.acnm.org/pubs/Clinical_Bulletin_5.pdf Schwayder JM: Pathophysiology of abnormal uterine bleeding. Obstet Gynecol Clin North Am 27:219-234, 2000.

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Foot Examination of the Patient with Diabetes Nikki Katalanos

PROCEDURE GOALS

AND

OBJECTIVES

Goals: To perform a thorough routine foot examination on the patient with diabetes. Objectives: The student will be able to …

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Describe the indications, contraindications, and rationale for performing a routine foot examination on the patient with diabetes.

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Describe the essential anatomy and physiology associated with examination of the foot of the patient with diabetes.

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Describe the logical order of steps used to perform a foot examination of the patient with diabetes.

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Describe normal and abnormal findings associated with examination of the foot of the patient with diabetes.

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Describe foot self-care information to be provided to the patient with diabetes for the prevention of future complications.

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Chapter 35—Foot Examination of the Patient with Diabetes Table 35.1

Categories of Diabetes Mellitus

From American Diabetes Association: Standards of medical care in diabetes. Diabetes Care 28:S4-S36, 2005.

Table 35.2

Criteria for the Diagnosis of Diabetes

From American Diabetes Association: Standards of medical care in diabetes. Diabetes Care 28:S4-S36, 2005.

BACKGROUND AND HISTORY Diabetes mellitus is a group of diseases that are characterized by higher than normal levels of blood sugar. The disease is a result of defects in insulin production or insulin action, or both (Table 35-1). The Centers for Disease Control and Prevention (CDC, 2004) estimates that the prevalence (existing cases) of diabetes across all ages is 18.2 million Americans, including 13 million diagnosed and 5.2 million undiagnosed cases. The incidence (new onset) is 1.3 million people per year. Regardless of type, the morbidity from this ubiquitous disease is quite costly, with total costs for direct care reaching $92 billion and costs for indirect care, which would include time lost from work, disability, and early death, adding another $40 billion. Lifestyle changes and early detection (Table 35-2) can delay or prevent many of the complications from diabetes. Estimates of the number of people with nervous system damage, ranging from mild to severe, directly caused by diabetes, is as high as 60% to 70%. As a result, the person with diabetes often has sensory or pain impairments in their hands and feet. In the United States, more than 60% of all nontraumatic amputations of the lower limb are among people with diabetes. According to the CDC (2004), aggressive foot care can reduce amputation by as much as 45% to 85%.

INDICATIONS The most common sequelae of diabetic neuropathy are foot ulceration, infection, and, ultimately, amputation. Early recognition and aggressive

Chapter 35—Foot Examination of the Patient with Diabetes management of foot care can prevent or delay the associated morbidity. The longer the person has diabetes, the greater the risk for ulcerations of the foot. Evidence indicates that these events are strongly related to poor glucose control and/or vascular co-morbidities. Risk factors that increase the potential for ultimate foot damage that may lead to amputation include the following: ■ Peripheral neuropathy ■

Increased pressure on the foot

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Deformities of the foot or toenails

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Peripheral vascular disease

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Previous history of foot ulcers (or amputation)

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Acute or chronic infection of the foot or toenails

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Poor foot hygiene

The patient with diabetes should be asked at each routine visit whether he or she has pain, numbness, or tingling sensations of the extremities. The patient should also be asked if he or she has any problems or leg cramping with walking, Any positive response to these questions warrants a comprehensive foot examination. In addition, note how far the patient can comfortably walk, and if the patient’s shoes are a comfortable fit. The value of the foot examination in a person with diabetes is well documented. The American Diabetes Association (2005) recommends that a comprehensive foot examination be performed annually on the low-risk patient and that a visual examination be conducted at each routine visit. Patients with any of the above-mentioned risk factors should be closely examined on a quarterly basis, at minimum.

CONTRAINDICATIONS There are no medical contraindications to the examination of the foot in a person with diabetes. In some cultures, however, the foot is considered unclean and should be the last part of the body that is examined.

POTENTIAL COMPLICATIONS There are no reported complications to this examination when the procedure is performed as described. The medical-legal concerns are that the clinician performs the examination incorrectly and too infrequently. It is essential that the method and tools used for examination be fully documented in the medical record. Many facilities use a diabetes flow chart for routine examinations.

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Chapter 35—Foot Examination of the Patient with Diabetes

REVIEW OF ESSENTIAL ANATOMY AND PHYSIOLOGY In order to perform the foot examination, an understanding of the anatomy of the vascular system is needed. Figure 35-1 shows the basic anatomy of the foot and the vascular supply of the lower extremities.

PATIENT PREPARATION After the diagnosis of diabetes has been made, the patient needs time to adjust and accept that many lifestyle changes will need to be made. The first visit is usually best spent discussing the disease itself and answering any questions the patient may have. The patient should be encouraged to view this as a partnership, one in which he or she will make many of the actual decisions with regard to self-care and treatment. A thorough history and physical examination should then be performed if time permits, or, at a minimum, at a timely follow-up visit. A foot examination, as described later, should be included in this initial evaluation. The diagnosis of diabetes, in particular type 2 diabetes, brings with it many preconceived notions and fears. Often there are family members with diabetes who have had bad experiences. Patients have heard stories of blindness, amputations, dialysis, and early death. The patient is often already conditioned to fear the disease and its consequences; therefore, it is essential that the initial approach to the patient with diabetes be reassuring and optimistic. Above all, the patient (or parents) should not be led to feel at fault for having developed diabetes. After the first visit, the preparation of the patient should include having the patient remove his or her shoes and socks before the examiner enters the room.

Materials Utilized for Performing the Diabetic Foot Examination ■

Semmes-Weinstein monofilament 5.07 (10 g) (Fig. 35-2)

■

128-Hz tuning fork

Chapter 35—Foot Examination of the Patient with Diabetes Common iliac artery

Abdominal aorta

External iliac artery

Internal iliac artery

Deep femoral artery

Common femoral artery

Superficial femoral artery

Popliteal artery

Anterior tibial artery Posterior tibial artery Peroneal artery

Medial malleolus Dorsalis pedis artery

A Popliteal vein Greater saphenous vein Lesser saphenous vein

Cartilage Phalanges bones

Metatarsal bones

Tarsal bones

Arteries and nerves

B

C

FIGURE 35-1. A, Arterial system of the lower extremity. B, Venous system of the lower extremity. C, Anatomy of the foot.

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FIGURE 35-2. Semmes-Weinstein monofilament.

Procedure for Performing the Diabetic Foot Examination The comprehensive foot examination entails visual inspection, palpation, and tests for sensation.

Visual Inspection The foot should always be examined with the shoes and socks off. The foot should be visually inspected at each routine visit for the following: 1. Color: Pale, bluish, or dusky coloration of the feet may mean poor perfusion. Erythema may indicate an area of excessive friction or it may be evidence of an ongoing or new infection. Yellow toenails may indicate a long-standing fungal infection. 2. Callus: Look for areas of skin thickening, particularly corns, callus, and over bunions. There may be an infection beneath the build-up. Evaluate the cause of the callus. Do the shoes fit well?

3. Fissures: Tears in the skin, particularly between the toes, are easy access to future infection. It may be a sign of a fungal infection or excessive moisture. 4. Ulcers: Look for signs of old or healing ulcerations. New ulcerations need to be immediately evaluated. 5. Maceration: Signs of excessive sweating, skin breakdown, or tinea pedis may also open avenues for infection. 6. Lack of hair: A possible indication of vascular disease—or is it just where the socks rub? 7. Toenails: Look for signs of fungal infections or injury. Are the toenails solidly adhered to the nail bed? Are they thickened or “flaky” looking? 8. Appearance: Look for misshapen feet that may forewarn of potential problems, such as bunions, hammertoes, “rocker” bottoms, or other soft tissue and bony deformities. Is the skin of the foot thin looking or shiny? Note hygiene as well.

Chapter 35—Foot Examination of the Patient with Diabetes 9. Shoe wear: Evaluate the shoes for signs of excessive pressure or friction on the feet. Are the shoes capable of protecting the foot from punctures or injury? Do they support the foot properly? 10. Socks: Do they fit the foot well? Are there areas of wear or holes?

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4. Edema: Press on the ankle and evaluate for pitting. If edema is present, the skin may crack easily.

Tests for Sensation

Palpation The foot should be palpated for the following: 1. Temperature: A cool or cold foot may mean poor perfusion. A warm foot, especially if the heat is localized, may be a sign of infection. 2. Pulses: Evaluate the pedal pulses. They should be strong (2+) and equal in both feet. 3. Perfusion: Press on the toenail and observe the capillary filling. A healthy foot reperfuses in 3 seconds or less. Greater than 5 seconds is an indication of poor perfusion.

Right foot

The tests for sensation allow the practitioner to evaluate for the presence of neuropathy. A focused history and physical examination should help to establish both the presence and degree of the neuropathy. Pain or temperature may also be checked, using great care, as part of the sensory evaluation. 1. Vibration: Press the vibrating tuning fork against the bony prominence of the first (big) toe on the dorsal-lateral aspect. Ask the patient to tell you when he or she feels the vibration start and when it stops. 2. Pressure: Press the monofilament lightly against the specified areas of the foot until it bows (Fig. 35-3). Record the presence or absence of sensation for each area tested.

Left foot

FIGURE 35-3. Demonstration of monofilament testing and areas of the foot that should be tested.

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Chapter 35—Foot Examination of the Patient with Diabetes

SPECIAL CONSIDERATIONS Consideration should be given to previous pathology (e.g., foot ulcers, deformities, tinea pedis). Tinea pedis can be very difficult to eradicate in any patient, but it is especially difficult in the patient with diabetes. Tinea pedis, minor infections, and shallow ulcerations can often be treated in the office. More severe cases and most deformities are best referred to podiatry, or in the case of infection, to an infectious disease consultant.

FOLLOW-UP CARE AND INSTRUCTIONS Patient education is critical in the prevention of future morbidity. There are many prepared handouts available, and a few of these resources are listed at the end of the chapter. General advice to the patient: ■ Check your feet every day. Look for cuts, sore spots, red spots, and blisters. A mirror can be used to see the bottom of the feet. A good way to use it is to mount it on the lower wall. ■

Wash your feet everyday. Use only warm water and a mild soap. Check the temperature of the water before getting into the tub or shower. Use the back of your hand. Clean carefully between the toes and dry the foot thoroughly. Apply a mild lubricating ointment to the heels and any dry areas. Do not use lotion between the toes.

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Keep the toenails trimmed. Be sure to trim straight across. Gently file the edges. Do this twice a month. Women should take off any toenail polish before being checked at the office.

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Always wear shoes and socks. Make sure the shoes are a good fit and do not pinch anywhere. Closed-toe shoes are safer, but sturdy sandals are fine. Check your shoes for foreign objects before putting them on. Socks should fit well, be without holes, and be kept clean and dry. Never, ever walk barefoot! Not even at the beach, where the sand can be hot enough to burn you.

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Check your blood sugar regularly. The best prevention of foot problems is well-controlled blood sugar.

REFERENCES American Diabetes Association: Standards of medical care in diabetes. Diabetes Care 28:S4-S36, 2005. Centers for Disease Control and Prevention. National diabetes fact sheet: General information and national estimates on diabetes in the United States, 2003, Rev. ed. Atlanta, Ga: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, 2004.

Chapter 35—Foot Examination of the Patient with Diabetes

BIBLIOGRAPHY American Podiatric Medical Association: Available at: http://www.apma.org/s_apma/index.asp Feet Can Last a Lifetime: A Health Care Provider’s Guide to Preventing Diabetes Foot Problems: An excellent resource for the practitioner that includes flow sheets and management plans for foot care. Available at: http://www.diabetic.com/education/feet/feet2/index.htm Habershaw GM: Management of the diabetic foot. In Leahy JL, Clark NG, Ceflu WT (eds): Medical Management of Diabetes Mellitus. Philadelphia, Saunders, 2000, pp 479-498. Slightly out of date, but still one of the best overall books on diabetes care. McCullock DK: Evaluation of the diabetic foot. Up To Date online 14.2.2006. Available at: www.utdol.com

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Procedural Sedation Tony Brenneman

PROCEDURE GOALS

AND

OBJECTIVES

Goal: To minimize patient discomfort while attempting to maintain spontaneous respirations and airway-protective reflexes in order to facilitate appropriate medical care. Objectives: The student will be able to …

•

Differentiate between conscious sedation and procedural sedation.

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Describe current JCAHO sedation care standards.

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Describe potential complications and techniques that may be employed to avoid or treat problems during sedation.

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Describe the essential anatomy and physiology associated with administration of procedural sedation.

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Identify the materials necessary for the administration of procedural sedation.

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Identify the agents used in procedural sedation, dosing methods, and discharge criteria.

Identify indications and contraindications for procedural sedation.

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Chapter 36—Procedural Sedation

BACKGROUND AND HISTORY Procedural sedation provides a way in which clinicians can perform diagnostic tests and clinical procedures that are sometimes painful or highly anxiety provoking in a manner that prevents or minimizes patient discomfort. Historically this method has been labeled conscious sedation, but this term has now become antiquated and imprecise, as all sedation causes some type of change in consciousness. The current accepted phrase is procedural sedation, which more accurately reflects the goal behind the process. Procedural sedation then refers to the techniques of managing a patient’s pain and anxiety to facilitate appropriate medical care in a safe, effective, and humane fashion (Brown, 2005), with the main goal being to minimize patient discomfort while attempting to maintain spontaneous respiration and airwayprotective reflexes. Procedural sedation is currently used in inpatient, emergency services and most outpatient settings. Practitioners must be aware of current guidelines and terminology in order to provide procedural sedation. The move to procedural sedation intimates that there is a continuum of sedation for the patient no matter the amount of sedative used. There also has been a lack of objective measures in levels of sedation. Based on this, criteria have been established to help define goal levels for procedural sedation. In 2001, the revised Joint Commission on Accreditation of Healthcare Organizations (JCAHO) sedation care standards replaced the term “conscious sedation” with “moderate sedation/analgesia” and attempted to provide clearer definitions of what this meant. The difficulty remains that this is still a subjective process and that each clinician must always be aware of how the patient is responding to the sedatives and dissociatives that he or she is being given. The JCAHO sedation guidelines provide qualitative goals for each practitioner while conducting procedural sedation, but ultimately we must strive to maintain safety by minimizing risks and ensuring safe discharge.

DEFINITIONS The progression from mild sedation to general anesthesia is a continuum, and definitions of sedation are evolving. Useful definitions include the following: ■ Analgesia—Relief of pain without intentionally producing a sedated state. Altered mental status may be a secondary effect of medications administered for analgesia. ■

Anxiolysis—A state of decreased apprehension concerning a particular situation; in this state, the level of awareness does not change.

The continuum of and definition of levels of sedation/analgesia according to the American Society of Anesthesiologists include: ■ Minimal sedation (anxiolysis)—A drug-induced state during which the patient responds normally to verbal commands. Cognitive function and

Chapter 36—Procedural Sedation coordination may be impaired, but ventilatory and cardiovascular function are unaffected. ■

Moderate sedation/analgesia (conscious sedation)—A drug-induced depression of consciousness during which the patient responds purposefully to verbal commands either alone or accompanied by light tactile stimulation. No interventions are required to maintain airway and adequate ventilation. Cardiovascular function is usually maintained.

■

Deep sedation/analgesia—A drug-induced depression of consciousness during which the patient cannot be easily aroused but responds purposefully following repeated or painful stimulation. The ability to independently maintain ventilatory function may require assistance in maintaining a patent airway and adequate ventilation. Cardiovascular function is usually maintained.

■

General anesthesia—A drug-induced loss of consciousness during which the patient cannot be aroused, even by painful stimulation. The ability to independently maintain ventilatory function is often impaired. The patient often requires assistance to maintain a patent airway, and positive-pressure ventilation may be required because of depressed spontaneous ventilation or drug-induced depression of neuromuscular function. Cardiovascular function may be impaired.

(Developed by the American Society of Anesthesiologists [ASA] and approved by the ASA House of Delegates, October 13, 1999. Referenced http://www. asahq.org/publicationsAndServices/sedation1017.pdf; accessed 07/15/05 at 1545.)

INDICATIONS Sedation/analgesia provides two general types of benefit: (1) sedation/ analgesia allows patients to tolerate unpleasant procedures by relieving anxiety, discomfort, or pain; and (2) in children and uncooperative adults, sedation/analgesia may expedite the conduct of procedures that are not particularly uncomfortable but that require the patient not move (ASA, 2002). Ultimately, the goals of procedural sedation and analgesia are to alleviate anxiety, minimize physical pain and discomfort, minimize negative psychological responses to treatment, maximize amnesia, control behavior to expedite performance of procedures, maintain safety by minimizing risks, and ensure safe discharge (Hsu, 2005).

CONTRAINDICATIONS Patients should be evaluated prior to the procedure for their suitability for sedation. From this a decision must be made if there are contraindications for sedation or anxiolytic medication use. Allergies to possible medications

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Chapter 36—Procedural Sedation used in the procedure may exclude the patient unless alternative medications may be substituted. Previous reactions to sedation or general anesthesia should be noted and may contraindicate the use of procedural sedation depending on the outcomes of prior use. Food ingested within the past 6 hours or clear liquids within the past 2 hours would preclude the patient from sedation unless there was an emergency situation involved, and then the benefits of the procedure must be weighed against the potential of aspiration. Absolute contraindications are uncommon, but the practitioner should consider comorbid illness or injury and the ability to manage the patient’s airway. Patients with significant comorbid cardiac, hemodynamic, or respiratory compromise should be approached with caution, as should patients who may be difficult to intubate or manually ventilate. If the patient is classified as a Class IV or V, as defined by the ASA physical status classification system, a nonanesthesiologist should not provide moderate sedation or anesthesia for that patient, but should refer the patient on to an anesthesiologist who may recommend general anesthesia or other treatment course (Table 36-1). Ultimately, the largest contraindication may be the practitioner. If the practitioner does not have the understanding of the medications administered, the ability to monitor the patient’s responses to the medications given, or the skills necessary to intervene in managing all potential complications, he or she should be excluded from performing the procedure with procedural sedation or anxiolytics. Practitioners also need to be in compliance with the institution’s requirements, whether special credentials and privileges are American Society of Anesthesiologists (ASA) Physical Status Classifications

Table 36.1

PATIENT CLASSIFICATION ASA 1: A normal, healthy patient. The pathologic process for which surgery is to be performed is localized and does not entail a systemic disease. ASA 2: A patient with systemic disease, caused either by the condition to be treated or other pathophysiologic process, but which does not result in limitation of activity ASA 3: A patient with moderate or severe systemic disease caused either by the condition to be treated surgically or other pathophysiologic process, which does limit activity ASA 4: A patient with severe systemic disease that is a constant potential threat to life ASA 5: A patient who is at substantial risk for death within 24 hr and is submitted to the procedure in desperation E: Emergency status—added to the ASA designation only if the patient is undergoing an emergency procedure

EXAMPLE An otherwise healthy patient scheduled for a cosmetic procedure A patient with asthma, diabetes, or hypertension that is well controlled with medical therapy, and has no systemic sequelae A patient with uncontrolled asthma that limits activity, or diabetes that has systemic sequelae such as retinopathy A patient with heart failure, or renal failure requiring dialysis A patient with fixed and dilated pupils status post head injury A healthy patient undergoing sedation for reduction of a displaced fracture, classified ASA 1E

Chapter 36—Procedural Sedation required, or if there are particular state, professional association, or regulatory body requirements to perform procedural sedation.

POTENTIAL COMPLICATIONS Complications to procedural sedation include, but are not limited to, vomiting, respiratory depression, hypoxia, hypotension, and cardiac arrest. The most serious complication is respiratory failure from airway obstruction or hypoventilation. Advanced airway management skills are a mandatory prerequisite for performing these techniques. Cardiac depression also may occur and must be rapidly recognized to avoid cardiac arrest or death. Complications are most likely to occur within 5 to 10 minutes after administration of intravenous medication and immediately after the procedure when procedural stimuli are removed (Krauss, 2000). Thus, monitoring should be especially close during these periods. These complications are less likely to occur when using alternative routes of administration, such as oral, nasal, rectal, or intramuscular, but these routes do not preclude them from occurring. Intravenous sedative/analgesic drugs should be given in small, incremental doses that are titrated to the desired end points of analgesia and sedation (ASA, 2002). Sufficient time must elapse between doses to allow the effect of each dose to be assessed before subsequent drug administration. When drugs are administered by nonintravenous routes (e.g., oral, rectal, intramuscular, transmucosal), allowance should be made for the time required for drug absorption before supplementation is considered. Because absorption may be unpredictable, administration of repeat dosing of oral medications to supplement sedation/analgesia is not recommended. As a practical consideration, unnecessary stimulation, such as inflation of a blood pressure cuff, may hinder the induction of sedation in a young or anxious child or adult. Once a complete set of vital signs has been obtained, deflate the cuff and monitor the patient visually until the drugs have begun to take effect. At this point, monitoring of pulse oximetry and heart rate, at a minimum, should be initiated. This could avoid additional doses of sedatives being given to the patient and pushing the patient into a much deeper level of depression than intended when the cuff is deflated or removed. Hepatic or renal abnormalities may impair drug metabolism and excretion, resulting in increased drug sensitivity and longer duration of drug action. This does not preclude the patient from procedural sedation, but the patient should be monitored closely. Medications that the patient is currently taking may interact with the sedatives and analgesics. Checking for specific drug interactions prior to starting the procedural sedation is recommended. Alcohol or illicit substance abuse may increase a patient’s tolerance to sedatives and analgesics. In addition, if the patient has been using these substances prior to sedation, the addition of sedatives/analgesics may be additive or synergistic and may require intubation earlier than anticipated with normal dosing of medications.

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Chapter 36—Procedural Sedation Tobacco use can increase the risk of airway irritability, bronchospasm, and coughing during sedation, requiring additional airway monitoring.

PATIENT PREPARATION Identify the patient by armband identification as well as verbal questioning. Be sure to ask the patient what procedure he or she is there for and that it is the correct procedure. Prior to giving any anxiolytic or analgesic medication, get consent for both the procedural sedation as well as the procedure that the patient is to undergo. The patient should be told of any risks involved with either the procedure or the sedation that is going to be used, as well as any post-sedation side effects to be expected. A directed history taking and physical examination should precede sedation (Krauss, 2000). Underlying medical problems should be assessed, and information about medication use, allergies, previous adverse experiences with sedation or general anesthesia, and the time and nature of the last oral intake should be obtained. Auscultation of the heart and lungs should be performed, vital signs taken, and the airway evaluated. Patients who have stridor, significant snoring, sleep apnea, advanced rheumatoid arthritis, dysmorphic facial features, Down’s syndrome, upper respiratory infections, or an abnormal airway examination (including Class III or class IV oral examination) should be considered to be at increased risk for airway obstruction during sedation. Also, these patients potentially have a difficult airway to manage if mask ventilation or intubation becomes necessary.

REVIEW OF ESSENTIAL ANATOMY AND PHYSIOLOGY A normal airway examination should consist of the following: ■ Opens mouth normally (Adults: greater than 2 finger widths or 3 cm) ■

Able to visualize at least part of the uvula and tonsillar pillars with mouth wide open and tongue out (patient sitting)

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Normal chin length (Adults: length of chin is greater than 2 finger widths or 3 cm)

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Normal neck flexion and extension without pain/paresthesias

An abnormal airway examination can consist of the following: ■ Small or recessed chin ■

Inability to open mouth normally

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Inability to visualize at least part of uvula or tonsils with mouth open and tongue out

Chapter 36—Procedural Sedation

Class I

Class II

Class III

Class IV

FIGURE 36-1. The progression of diagrams from left to right suggests increased difficulty in airway management during sedation (Hata, 2005). (Referenced May 9, 2005: http://www.vh.org/adult/provider/anesthesia/ProceduralSedation)

■

High arched palate

■

Tonsillar hypertrophy

■

Neck with limited range of motion

■

Low-set ears

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Significant obesity of the face and neck

■

Class III or Class IV oral examination (Fig. 36-1)

Materials Utilized for Procedural Sedation Although rare, procedural sedation and analgesia may result in an allergic reaction, respiratory arrest, or cardiopulmonary arrest (Godwin, 2005). The incidence of complications is dependent on the drugs used, rate and dose of administration, and patient sensitivities. Although the literature is mixed regarding what specifically needs to be at bedside, there is clear agreement that pulse oximetry be performed. In addition, if the patient has a history of cardiac disease, ongoing monitoring with electrocardiography should be performed. Other equipment that must be immediately available, but not necessarily at bedside, includes: ■ Pharmacologic antagonists and appropriately sized equipment for establishing a patent airway and providing positive-pressure ventilation with supplemental oxygen ■

Suction, advanced airway equipment, and resuscitation medication, which should be immediately available and in good working order

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Chapter 36—Procedural Sedation ■

A functional defibrillator for whenever deep sedation is administered and when moderate sedation is administered to patients with mild or severe cardiovascular disease

Intravenous access should be maintained when intravenous procedural sedation and analgesia is provided (Godwin, 2005). Intravenous access may not be necessary when procedural sedation and analgesia is provided by other routes.

MONITORING Monitoring the patient during sedation involves visual observation for ventilatory function, response to verbal commands (unless they are unable to respond in a meaningful way [e.g., very young children]), and determination of vital signs at regular intervals. Monitoring of exhaled carbon dioxide should be considered for all patients receiving deep sedation and for patients whose ventilation cannot be directly observed during moderate sedation. Vital signs should be recorded at specific and regular intervals. At a minimum this should include before starting the procedure, after administration of the drug, when the procedure is complete, during early recovery, and when recovery is completed and patient is ready for discharge. Capnography, or monitoring of exhaled carbon dioxide, is becoming increasingly available and may be useful in assessing ventilation during sedation and analgesia. Capnometry is a technique used to monitor end tidal CO2 and, therefore, may detect early cases of inadequate ventilation before oxygen desaturation takes place (Godwin, 2005). This is currently not required by any of the literature but has been indicated as useful when ventilatory monitoring is impaired or if the patient is unable to respond to verbal stimuli during the procedure itself.

AGENTS FOR PROCEDURAL SEDATION The appropriate choice of agents and techniques that are used for sedation or analgesia is practitioner dependent and reflects the comfort level and experience that he or she has with administering the particular medication. It also is dependent on the constraints imposed by the patient, supervising physician, type of procedure, and the facility. Once these constraints are identified, the choices of analgesics/sedatives may be more limited. The following are common medications used in sedation and analgesia to achieve minimal to moderate sedation. However, one must keep in mind that all of these drugs have the potential to push the patient into deep sedation, requiring airway management, reversing agents, cardiac dysfunction, and need for additional airway support. Therefore, the practitioner should be

Chapter 36—Procedural Sedation

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able to rescue patients whose level of sedation becomes deeper than initially intended. Multiple agents and various combinations of agents can be used to provide sedation and analgesia. Opioids are used primarily when analgesia is required. Sedation is often an added benefit for the patient’s comfort during the procedure, but it is not the primary indication for administration. Benzodiazepines and other sedatives, such as barbiturates and chloral hydrate, are useful medications when achieving anxiolysis and amnesia. They are best given just prior to a procedure or during the procedure itself. When considering the selection of an agent, it is important to consider the properties of the agent as well as the type of procedure that is being performed (painful or nonpainful). This can dictate using only one medication as opposed to multiple medications and possibly drug-drug interaction. However, if the procedure is painful and the patient would benefit from an anxiolytic, it is appropriate to use a combination of opioids and benzodiazepines, recognizing that there is an additive/synergistic effect of these medications and that additional monitoring will be required. These medications are listed in Tables 36-2 and Table 36.2 AGENT Fentanyl

Opioids ROUTE IV—Adult

IV—Peds

Morphine

IV—Adult

IV—Peds

Meperidine

IV—Adult

IV—Peds

USUAL DOSAGE Start with 0.5-0.1 μg/kg over 2 min Titrate 0.25-0.5 μg/kg every 5 min to a maximum of 4-5 μg/kg Start with 0.5 μg/kg over 2 min Titrate 0.25-0.5 μg/kg every 5 min Initial dose 3-4 mg over 2 min Titrate 1-2 mg every 5 min Initial dose 0.05 mg/kg over 2 min Titrate 0.02-0.05 mg/kg every 5-10 min Start with 25-50 mg over 2 min Titrate 10-15 mg every 5 min to a maximum of 150 mg total Start with 0.5 mg/kg over 2 min Titrate 0.25-0.5 mg/kg every 5 min

ONSET/PEAK

DURATION

COMMENTS Analgesia, reversible with naloxone

1-2 min/3-5 min

30-60 min

Respiratory depression increased with other respiratory depressants, cardiacarrhythmias increased

2-5 min/20 min

4-5 hr

Analgesia, reversible with naloxone Respiratory depression increased with other respiratory depressants, hypotension possible

5 min/20 min

CNS, central nervous system; IV, intravenous; Peds, pediatric population.

2-4 hr

Analgesia, reversible with naloxone, produces generalized CNS depression and increased respiratory depression with additional agents

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Chapter 36—Procedural Sedation

Table 36.3 AGENT Midazolam

Benzodiazepines ROUTE IV—Adult

IV—Peds

PO—Peds Diazepam

IV—Adult

PO—Adult Lorazepam

IV—Adult

PO—Adult

USUAL DOSAGE ONSET/PEAK Initial dose 0.02 mg/kg or 0.5-2 mg over 2 min Titrate by 0.5 mg 1-3 min/3-5 min every 5 min to a maximum of 5 mg total Initial dose 0.05 to 0.l mg/kg over 2 min Titrate by 0.025 mg/kg every 5 min, not to exceed a cumulative dose of 0.6 mg/kg 0.25-0.75 mg/kg 10-20 min/ 20-50 min Initial dose 2.5-5 mg over 5 min Titrate by 2.0-2.5 mg every 5 min Note: Not 1-5 min/5-8 min recommended for pediatric patients due to long duration 5-10 mg 30-60 min/ 30-90 min Initial dose 0.5 mg to 2 mg over 5 min Titrate to a maximum 5 min/15-20 min dose of 4 mg Initial dose 2 mg May repeat times once after 20-30 min Note: Not 20-30 min/ recommended for 60-90 min pediatric patients due to long duration

DURATION

COMMENTS